JP2009085216A - Rotation type fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce vibration caused by swinging movement generated in each compression mechanism 20, 50 of a compressor 1 constituted by arranging and superposing the compression mechanisms 20, 50 in a double-layer state having cylinders 21, 51 having annular cylinder chambers C1, C2, C3, C4 and annular pistons 22, 52 stored in the cylinder chambers C1, C2, C3, C4 in an eccentric state. <P>SOLUTION: The rotation type fluid machine is constituted so that the annular pistons 22, 52 can make an eccentric rotary motion with respect to the cylinders 21, 51. Both of the piston mechanisms 20, 50 are arranged so that the swinging movement generated with the eccentric rotary motion of the first compression mechanism 20 and the swinging movement generated with the eccentric rotary motion of the second compression mechanism 50 have a phase difference which makes both of the swinging movement balance each other out. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotary fluid machine, and in particular, a rotary type in which eccentric rotary piston mechanisms having a cylinder having an annular cylinder chamber and an annular piston housed eccentrically in the cylinder chamber are arranged in two stages. The present invention relates to a fluid machine.

  Conventionally, an eccentric rotary piston mechanism that includes a cylinder having a cylinder chamber and a piston that is eccentrically housed in the cylinder chamber and compresses fluid by a change in volume of the cylinder chamber accompanying an eccentric rotational movement of the piston is provided. A rotary fluid machine is known.

  For example, Patent Document 1 discloses a compressor including two eccentric rotation type piston mechanisms (compression mechanisms). The compressor disclosed in Patent Document 1 includes a drive motor, a drive shaft driven by the drive motor, and first and second eccentric rotary piston mechanisms connected to the drive shaft and arranged in two upper and lower stages. It has. This compressor is configured to be switchable between a single-stage compression operation or a two-stage compression operation.

  Patent Document 2 discloses a compressor including an eccentric rotary piston mechanism having a cylinder having an annular cylinder chamber and an annular piston housed eccentrically in the cylinder chamber. The annular piston has a C-shape obtained by dividing a part of the annular ring, and is integrally formed with a housing fixed to the casing of the compressor. On the other hand, the cylinder is connected to the eccentric portion of the drive shaft of the compressor, and extends from the inner peripheral wall surface to the outer peripheral wall surface of the annular cylinder chamber through the dividing portion of the annular piston. The blade is integrally formed.

A swing bush is provided between the blade and the annular piston, and the annular piston and the cylinder are swingably connected via the swing bush.
Japanese Unexamined Patent Publication No. 64-010066 JP-A-2005-337012

  By the way, it is conceivable to construct a rotary fluid machine by stacking the eccentric rotary piston mechanism shown in Patent Document 2 in two stages as shown in Patent Document 1. However, if the eccentric rotary piston mechanism disclosed in Patent Document 2 is simply stacked in two stages, the rotary fluid machine may vibrate greatly due to the swinging moment generated in each eccentric rotary piston mechanism. is there.

  The present invention has been made in view of such a point, and an object of the present invention is to provide an eccentric rotary piston mechanism having a cylinder having an annular cylinder chamber and an annular piston housed eccentrically in the cylinder chamber in two stages. In the rotary fluid machine arranged so as to overlap with each other, the vibration caused by the swinging moment generated in each eccentric rotary piston mechanism can be reduced.

  The first invention includes a first eccentric rotary piston mechanism (20) and a second eccentric rotary piston mechanism (50) arranged in two stages, and the eccentric rotary piston mechanisms (20, 50). A drive mechanism (30) having a drive shaft (33) for driving, and each eccentric rotary piston mechanism (20, 50) is a cylinder (21, 50) having an annular cylinder chamber (C1, C2, C3, C4) 51) and the cylinder chambers (C1, C2, C3, C4) so as to partition the cylinder chambers (C1, C2, C3, C4) into an outer cylinder chamber (C1, C3) and an inner cylinder chamber (C2, C4). ) And an annular piston (22, 52) housed eccentrically, and a rotating fluid (23) that divides each cylinder chamber (C1, C2, C3, C4) into a first chamber and a second chamber. The machine is assumed.

  The annular piston (22, 52) is configured to perform an eccentric rotational motion with respect to the cylinder (21, 51) of the rotary fluid machine, so that the first eccentric rotational piston mechanism (20) can perform the eccentric rotational operation. Both piston mechanisms (20, 50) are arranged so that the phase difference in which the oscillation moment that accompanies the oscillation moment and the oscillation moment that accompanies the eccentric rotation operation of the second eccentric rotation piston mechanism (50) cancel each other out. It is characterized by being.

  Here, in the first and second eccentric rotary piston mechanisms (20, 50), the cylinder (21, 51) is fixed and the annular piston (22, 52) is movable (hereinafter, piston movable system). (Referred to as “movable bushing”)), and as shown in Patent Document 2, the annular piston (22, 52) is fixed to the housing, and the cylinder (21, 51) is connected to the drive shaft (33) to be movable. This is the opposite of the method (hereinafter referred to as the piston fixing method (fixed bushing method)).

  In the piston fixing method, as will be described later, an unbalance occurs in the swing moment during rotation of the drive shaft (33). However, in the movable piston method, an unbalance occurs in the swing moment during rotation of the drive shaft (33). Hateful. Therefore, when the first and second eccentric rotary piston mechanisms (20, 50) are of the piston fixing type, the swing moments of the first eccentric rotary piston mechanism (20) and the second eccentric rotary piston mechanism (50) are used. Even if a phase difference is added between the two, the oscillation moments do not cancel each other.

  In the first invention, the first and second eccentric rotary piston mechanisms (20, 50) are of a piston movable type, and the swinging moments generated in each of the eccentric rotary piston mechanisms (20, 50) are in a predetermined position. By arranging both piston mechanisms (20, 50) so as to have a phase difference, it is possible to cancel each oscillation moment.

  According to a second invention, in the first invention, the phase difference between the swing moment generated by the first eccentric rotary piston mechanism (20) and the swing moment generated by the second eccentric rotary piston mechanism (50) is the same. It is characterized by being set to 180 °.

  In the second invention, both piston mechanisms (20, 50) are arranged such that the swinging moments generated in each of the first and second eccentric rotary piston mechanisms (20, 50) have a phase difference of 180 °. Is arranged. Thereby, it is possible to effectively cancel each oscillation moment.

  The third invention is characterized in that, in the first or second invention, the magnitudes of swinging moments of the first eccentric rotary piston mechanism (20) and the second eccentric rotary piston mechanism (50) are equal. Yes.

  In the third aspect of the invention, the magnitudes of the swinging moments generated in the first and second eccentric rotary piston mechanisms (20, 50) are equal, so that the swinging moments effectively cancel each other out. . In particular, if a phase difference of 180 ° is generated between the swing moments, the swing moments cancel each other more effectively.

  The swing moment is the product of the piston inertia moment and swing angular acceleration. Piston inertia moment × e (the eccentric amount in FIG. 8) / L (the fulcrum (M1) in FIG. 8 and the center of the annular piston (M3) This is a value proportional to the distance. If the inertia moment of the main body of the first eccentric rotary piston mechanism (20) is different from that of the second eccentric rotary piston mechanism (50), it can be swung by adjusting the inertia moment of the end plate, e dimension and L dimension. The moment can be adjusted.

  A fourth invention is the first, second or third invention, wherein the annular pistons (22, 52) of the first eccentric rotary piston mechanism (20) and the second eccentric rotary piston mechanism (50) are Each has an annular piston main body (22b, 52b) and a piston side end plate (22c, 52c) formed at the axial end of the annular piston main body (22b, 52b), and an eccentric rotation type piston mechanism Is characterized in that when the axial length of the annular piston body is smaller than the other, the thickness of the piston side end plate is larger than the other.

  In the fourth aspect of the invention, the axial length of the annular piston main body and the thickness of the piston side end plate are adjusted to generate each of the first and second eccentric rotary piston mechanisms (20, 50). The magnitude of the swinging moment can be changed. And it can set to the magnitude | size in which rocking moments cancel each other effectively.

  According to a fifth invention, in the first, second or third invention, the first eccentric rotary piston mechanism (20) and the second eccentric rotary piston mechanism (50) are configured using the same components. It is characterized by being.

  In the fifth invention, the first and second eccentric rotary piston mechanisms (20, 50) are constituted by the same components, so that both piston mechanisms (20, 50) of the second invention are similar to the fourth invention. It is possible to effectively cancel the oscillation moment generated in each.

  A sixth invention is characterized in that, in any one of the first to fifth inventions, the first eccentric rotary piston mechanism (20) and the second eccentric rotary piston mechanism (50) are compression mechanisms. .

  In the sixth invention, when the first and second eccentric rotary piston mechanisms (20, 50) constitute a compression mechanism, both piston mechanisms (20, 50) are of a piston movable type, and each eccentric rotary type. By arranging both piston mechanisms (20, 50) so that the oscillation moments generated in the piston mechanisms (20, 50) have a predetermined phase difference, the oscillation moments cancel each other. Can do.

  According to a seventh aspect, in the sixth aspect, the first eccentric rotary piston mechanism (20) and the second eccentric rotary piston mechanism (50) constitute a two-stage compression mechanism that compresses the working fluid in two stages. It is characterized by having.

  In the seventh invention, in the rotary fluid machine having the two-stage compression mechanism, the swinging moments generated in each of the first and second eccentric rotary piston mechanisms (20, 50) are canceled out. it can.

  An eighth invention is characterized in that, in the sixth or seventh invention, the working fluid is carbon dioxide.

  In the eighth invention, in the rotary fluid machine using carbon dioxide as the working fluid, the swing moments generated in each of the first and second eccentric rotary piston mechanisms (20, 50) cancel each other. Can do.

  According to the present invention, in the rotary fluid machine described above, the first and second eccentric rotary piston mechanisms (20, 50) are of a piston movable type, and the swing moment of each eccentric rotary piston mechanism (20, 50). By arranging the two piston mechanisms (20, 50) so that they have a predetermined phase difference, the swinging moments can cancel each other. Therefore, in the rotary fluid machine, vibrations caused by the swing moments of the first and second eccentric rotary piston mechanisms (20, 50) can be reduced.

  According to the second invention, in the rotary fluid machine, the first and second eccentric rotary piston mechanisms (20, 50) are moved to the piston movable system, and both the piston mechanisms (20, 50) Both piston mechanisms (20, 50) are arranged so that the generated oscillation moments have a phase difference of 180 °. As a result, the swing moment generated in each of both piston mechanisms (20, 50) can be effectively canceled, and the vibration of the rotary fluid machine caused by the swing moment of each piston mechanism can be effectively reduced. can do.

  According to the third invention, since the magnitudes of the swinging moments generated in each of the first and second eccentric rotary piston mechanisms (20, 50) are made equal, each swinging moment is effective. Counteracting effects occur. Therefore, the vibration of the rotary fluid machine due to the swinging moment of each piston mechanism can be effectively reduced. In particular, if the magnitudes of the swing moments are made equal and a phase difference of 180 ° is generated, the swing moments cancel each other more effectively, thereby further enhancing the vibration preventing effect.

  According to the fourth invention, each of the first and second eccentric rotary piston mechanisms (20, 50) is adjusted by adjusting the axial length dimension of the annular piston body and the thickness dimension of the piston side end plate. By changing the magnitude of the oscillation moment generated in the cylinder, it is possible to set the oscillation moments so that the oscillation moments effectively cancel each other. Can be effectively reduced.

  According to the fifth aspect of the present invention, in the rotary fluid machine, the first and second eccentric rotary piston mechanisms (20, 50) are of the piston movable type, and both the piston mechanisms (20, 50) are the same. Consists of components. As a result, as in the second invention, the swinging moment generated in each of the piston mechanisms (20, 50) can be effectively canceled out, and the rotary fluid caused by the swinging moment of each piston mechanism. The vibration of the machine can be effectively reduced.

  Both piston mechanisms (20, 50) are composed of the same components, and the swinging moments generated in both piston mechanisms (20, 50) have a phase difference of 180 °. If both piston mechanisms (20, 50) are arranged, the oscillation moment generated in each of both piston mechanisms (20, 50) can be more effectively canceled out.

  According to the sixth aspect of the invention, when the rotary fluid machine constitutes a compressor, the first and second eccentric rotary piston mechanisms (20, 50) are piston movable types, and each eccentric rotation is performed. By arranging the two piston mechanisms (20, 50) so that the swinging moments of the piston piston mechanism (20, 50) have a predetermined phase difference, the swinging moments cancel each other out. it can. Therefore, in the compressor, it is possible to reduce vibrations caused by the swing moments of the first and second eccentric rotary piston mechanisms (20, 50).

  According to the seventh aspect of the present invention, in the rotary fluid machine having the two-stage compression mechanism, the swing moments generated in each of the first and second eccentric rotary piston mechanisms (20, 50) cancel each other. Therefore, vibration caused by the swinging moment of each piston mechanism can be effectively reduced.

  According to the eighth aspect of the present invention, in the rotary fluid machine using carbon dioxide as the working fluid, the swinging moments generated in each of the first and second eccentric rotary piston mechanisms (20, 50) cancel each other. Therefore, vibration caused by the swinging moment of each piston mechanism can be effectively reduced.

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

Embodiment 1 of the Invention
A first embodiment of the present invention will be described.

-Embodiment (movable bush system)-
1 is a longitudinal sectional view of a rotary compressor (1) according to this embodiment, FIG. 2 is a transverse sectional view of a first compression mechanism (20), and FIG. 3 is an operational state diagram of the first compression mechanism (20). It is. Note that the cross-sectional view and the operation state diagram of the second compression mechanism (50) are the same as those of the first compression mechanism (20), and the description thereof will be omitted.

  As shown in FIG. 1, the compressor (1) includes a first compression mechanism (first eccentric rotary piston mechanism) (20) and a second compression mechanism (second eccentric rotary piston) in a casing (10). The mechanism) (50) and the electric motor (drive mechanism) (30) are accommodated, and are configured as a completely sealed type. 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 upper end panel (12). It has been.

  The first compression mechanism (20) and the second compression mechanism (50) are stacked in two upper and lower stages, and are configured between a front head (16) and a rear head (17) fixed to the casing (10). Yes. The first compression mechanism (20) is disposed on the electric motor side (upper side in FIG. 1), and the second compression mechanism (50) is disposed on the bottom side (lower side in FIG. 1) of the casing (10).

  The first compression mechanism (20) includes a first cylinder (21) having an annular first cylinder chamber (C1, C2) and a first annular piston disposed in the first cylinder chamber (C1, C2). (22) and as shown in FIGS. 2 and 3, the first cylinder chamber (C1, C2) is a first chamber, a high pressure chamber (compression chamber) (C1-Hp, C2-Hp), and a second chamber. The first blade (23) is divided into a low pressure chamber (suction chamber) (C1-Lp, C2-Lp).

  On the other hand, the second compression mechanism (50) has the same configuration as the first compression mechanism (20) and is vertically inverted with respect to the first compression mechanism (20). The second compression mechanism (50) includes a second cylinder (51) having an annular second cylinder chamber (C3, C4), and a second annular piston disposed in the second cylinder chamber (C3, C4). (52) and a second blade (not shown) that divides the second cylinder chamber (C3, C4) into a high pressure chamber (not shown) as the first chamber and a low pressure chamber (not shown) as the second chamber. have.

  In this embodiment, the front head (16) constitutes the first cylinder (21), and the rear head (17) constitutes the second cylinder (51). In the present embodiment, the first cylinder (21) having the first cylinder chambers (C1, C2) and the second cylinder (51) having the second cylinder chambers (C3, C4) are on the fixed side and have the first annular shape. The piston (22) and the second annular piston (52) are movable, the first annular piston (22) performs eccentric rotational movement with respect to the first cylinder (21), and the second annular piston (52) It is comprised so that eccentric rotation motion may be carried out with respect to 2 cylinders (51). In the following description, a method in which the annular piston (22) is movable as in the present embodiment is referred to as a movable bush method (piston movable method), and a method in which the annular piston (22) is fixed is a fixed bush. This is called a system (piston fixing system).

  The electric motor (30) includes a stator (31) and a rotor (32). The stator (31) is disposed above the first 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) passes through the first cylinder chamber (C1, C2) and the second cylinder chamber (C3, C4) 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 in the bottom of the casing (10) is slid between the sliding portion of the first compression mechanism (20) and the second compression mechanism (50) through the oil supply passage by the oil pump (34). To supply to the department.

  The drive shaft (33) has a first eccentric portion (33a) formed in a portion located in the first cylinder chamber (C1, C2), and a portion located in the second cylinder chamber (C3, C4). The second eccentric portion (63a) is formed in the upper portion. The first eccentric portion (33a) is formed with a larger diameter than the portion above the first eccentric portion (33a), and is eccentric from the axis of the drive shaft (33) by a predetermined amount. The second eccentric portion (63a) is formed to have the same diameter as the first eccentric portion (33a), and is eccentric from the axis of the drive shaft (33) by the same amount as the first eccentric portion (33a). The first eccentric portion (33a) and the second eccentric portion (63a) are 180 ° out of phase with each other about the axis of the drive shaft (33).

  The first annular piston (22) is an integrally formed member, and a first bearing portion (22a) slidably fitted to a first eccentric portion (33a) of the drive shaft (33); A first annular piston main body (22b) positioned concentrically with the first bearing (22a) on the outer peripheral side of the first bearing (22a), a first bearing (22a) and a first annular piston main body (22b) and a first piston side end plate (22c), and the first annular piston main body (22b) is formed in a C shape in which a part of the annular ring is divided.

  Similarly to the first annular piston (22), the second annular piston (52) is an integrally formed member, and is slidable on the second eccentric portion (63a) of the drive shaft (33). A second bearing portion (52a) to be fitted, a second annular piston main body portion (52b) positioned concentrically with the second bearing portion (52a) on the outer peripheral side of the second bearing portion (52a), and a second A second piston-side end plate (52c) connecting the bearing portion (52a) and the second annular piston main body portion (52b) is provided, and the second annular piston main body portion (52b) is partly cut off from a ring. It is formed in a C shape.

  The first cylinder (21) includes a first inner cylinder part (21b) positioned concentrically with the drive shaft (33) between the first bearing part (22a) and the first annular piston body part (22b). A first outer cylinder portion (21a) concentric with the first inner cylinder portion (21b) on the outer peripheral side of the first annular piston main body portion (22b), a first inner cylinder portion (21b) and a first outer side A first cylinder side end plate (21c) connecting the cylinder part (21a) is provided.

  The second cylinder (51) includes a second inner cylinder part (51b) positioned concentrically with the drive shaft (33) between the second bearing part (52a) and the second annular piston body part (52b). A second outer cylinder part (51a) positioned concentrically with the second inner cylinder part (51b) on the outer peripheral side of the second annular piston body part (52b), a second inner cylinder part (51b) and a second outer side A second cylinder-side end plate (51c) that connects the cylinder part (51a) is provided.

  The front head (16) and the rear head (17) are 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 first cylinder chamber (C1, C2) and the second cylinder chamber (C3, C4) in the vertical direction, The first eccentric part (33a) and the second eccentric part (63a) have a through-shaft structure in which both side portions in the axial direction are held by the casing (10) via bearing parts (16a, 17a).

  Next, the internal structures of the first and second compression mechanisms (20, 50) will be described. Since they have the same configuration as described above, the first compression mechanism (20) will be described as a representative example.

  As shown in FIG. 2, the first compression mechanism (20) is capable of swinging the first annular piston (22) with respect to the first blade (23) at the dividing position of the first annular piston (22). A first swing bush (27) is provided as a connecting member to be connected to. The first blade (23) is arranged on the inner circumferential wall surface of the first cylinder chamber (C1, C2) (the outer periphery of the first inner cylinder portion (21b)) on the radial line of the first cylinder chamber (C1, C2). Surface) to the outer peripheral wall surface (inner peripheral surface of the first outer cylinder portion (21a)), and is configured to extend through the dividing portion of the first annular piston (22). (21a) and the first inner cylinder part (21b). The first blade (23) may be formed integrally with the first outer cylinder part (21a) and the first inner cylinder part (21b), or separate members may be provided on both cylinder parts (21a, 21b). It may be attached. 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 first outer cylinder portion (21a) and the outer peripheral surface of the first inner cylinder portion (21b) are cylindrical surfaces arranged on the same center, and the first cylinder chambers (C1, C2) between them. ) Is formed. The first annular piston (22) has an outer peripheral surface having a smaller diameter than an inner peripheral surface of the first outer cylinder portion (21a) and an inner peripheral surface having a larger diameter than an outer peripheral surface of the first inner cylinder portion (21b). Is formed. Thus, a first outer cylinder chamber (C1) is formed between the outer peripheral surface of the first annular piston (22) and the inner peripheral surface of the first outer cylinder portion (21a), and the first annular piston (22) A first inner cylinder chamber (C2) is formed between the inner peripheral surface of the first inner cylinder portion and the outer peripheral surface of the first inner cylinder portion (21b).

  Specifically, the first outer cylinder chamber is located between the first cylinder side end plate (21c), the first piston side end plate (22c), the first outer cylinder portion (21a), and the first annular piston body portion (22b). (C1) is formed, the first inner side between the first cylinder side end plate (21c), the first piston side end plate (22c), the first inner cylinder part (21b) and the first annular piston body part (22b). A cylinder chamber (C2) is formed. Further, between the first cylinder side end plate (21c), the first piston side end plate (22c), the first bearing portion (22a) of the first annular piston (22), and the first inner cylinder portion (21b), An operation space (25) for allowing the eccentric rotation operation of the first bearing portion (22a) is formed on the inner peripheral side of the first inner cylinder portion (21b).

  The first annular piston (22) and the first cylinder (21) are substantially in contact at one point with the outer peripheral surface of the first annular piston (22) and the inner peripheral surface of the first outer cylinder part (21a). The inner circumferential surface of the first annular piston (22) at a position that is 180 ° out of phase with the contact point in a state (strictly speaking, there is a micron-order gap, but leakage of refrigerant in the gap is not a problem). And the outer peripheral surface of the first inner cylinder part (21b) are substantially in contact with each other at one point.

  The first oscillating bush (27) includes a discharge side bush (27A) positioned on the high pressure chamber (C1-Hp, C2-Hp) side with respect to the first blade (23), and a first blade (23). On the other hand, it is composed of a suction side bush (27B) located on the low pressure chamber (C1-Lp, C2-Lp) side. 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 first blade (23) is inserted into the blade groove (28), and the flat surface of the first swing bush (27A, 27B) substantially comes into surface contact with the first blade (23). (27A, 27B) The arc-shaped outer peripheral surface is substantially in surface contact with the first annular piston (22). The first swing bushes (27A, 27B) are configured to advance and retreat in the surface direction of the first blade (23) with the first blade (23) sandwiched between the blade grooves (28). The first swing bush (27A, 27B) is configured such that the first annular piston (22) swings with respect to the first blade (23). Therefore, in the first swing bush (27), the first annular piston (22) swings with respect to the first blade (23) with the center point of the first swing bush (27) as the swing center. The first annular piston (22) is configured to be able to advance and retract in the surface direction of the first blade (23) with respect to the first 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 configuration described above, when the drive shaft (33) rotates, the first annular piston (22) moves the first swing bush while the first swing bush (27) advances and retreats along the first blade (23). Swing around the center point of (27). When the drive shaft (33) rotates, the second annular piston (52) also swings around the center point of the second swing bush (not shown) as the swing center, like the first annular piston (22). Move.

  By this swinging operation, the first contact point between the first annular piston (22) and the first cylinder (21) is moved in order from FIG. 3 (A) to FIG. 3 (H). On the other hand, the second contact point between the second annular piston (52) and the second cylinder (51) is shifted by 180 ° around the axis of the drive shaft (33) with respect to the first contact point. That is, when the operating state of the first compression mechanism (20) is FIG. 3 (A) when viewed from above the drive shaft (33), the operating state of the second compression mechanism (50) is FIG. 3 (E). .

  FIG. 3 is a view showing the operating state of the movable bush type first compression mechanism (20), and the first annular piston (22) is shown at 45 ° intervals from FIG. 3 (A) to FIG. 3 (H). It shows a state of moving in the clockwise direction. At this time, the first annular piston (22) revolves while swinging 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 first outer cylinder chamber (C1). The first annular piston (22) communicates with the low pressure chamber (C1-Lp) of the first outer cylinder chamber (C1) and the low pressure chamber (C2-Lp) of the first inner cylinder chamber (C2). A through hole (44) is formed.

  On the other hand, the rear head (17) is formed so that the suction port (41) to which the suction pipe (14) is connected communicates with the low pressure chamber of the second outer cylinder chamber (C3), similarly to the front head (16). Has been. The second annular piston (52) has a through hole (44) that communicates the low pressure chamber of the second outer cylinder chamber (C3) and the low pressure chamber of the first inner cylinder chamber (C2). .

  Further, as shown in FIG. 2, the front head (16) has a first outer discharge port (45) and a first inner discharge port (46). These discharge ports (45, 46) respectively penetrate the first cylinder side end plate (21c) of the front head (16) in the axial direction thereof. The lower end of the first outer discharge port (45) opens to face the high pressure chamber (C1-Hp) of the first outer cylinder chamber (C1), and the lower end of the first inner discharge port (46) is the first inner cylinder chamber. It opens to face the high pressure chamber (C2-Hp) of (C2). On the other hand, the upper ends of these discharge ports (45, 46) communicate with the discharge space (49) via discharge valves (not shown) that open and close the discharge ports (45, 46).

  On the other hand, although not shown, the rear head (17) is also formed with a second outer discharge port (not shown) and a second inner discharge port (not shown). These discharge ports respectively penetrate the second cylinder side end plate (21c) of the rear head (17) in the axial direction thereof. The lower end of the second outer discharge port opens to face the high pressure chamber of the second outer cylinder chamber (C3), and the lower end of the second inner discharge port opens to face the high pressure chamber of the second inner cylinder chamber (C4) is doing. The upper ends of these discharge ports communicate with the discharge space (49) via a discharge valve (not shown) that opens and closes the discharge ports.

  These discharge spaces (49) are formed between the front head (16) and the first cover member (18) and between the rear head (17) and the second cover member (48), respectively. The first cover member (18) discharges the discharge gas from the first compression mechanism (20) into the discharge space (49) once, and then the first cover member (18), 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 the discharge opening (18a) between them is configured. On the other hand, the second cover member (48), like the first cover member (18), once discharges the discharge gas from the second compression mechanism (50) into the discharge space (49). 2 A muffler mechanism for obtaining a silencing function by flowing out into the high-pressure space (19) in the casing (10) through the discharge opening (48a) between the cover member (48) and the bearing portion (17a) is configured. .

-Driving action-
Next, the operation of the compressor (1) will be described. Here, the operation of the first and second compression mechanisms (20, 50) is performed in a state of being shifted from each other by 180 °. Since the operations are the same except for the phase, the operation of the first compression mechanism (20) will be described as a representative.

  When the electric motor (30) is started, the rotation of the rotor (32) is transmitted to the first annular piston (22) of the first compression mechanism (20) via the drive shaft (33). Then, the first swing bush (27A, 27B) reciprocates (advances and retracts) along the first blade (23), and the first annular piston (22) and the first swing bush (27A, 27B). ) Integrally move to swing the first blade (23). At that time, the first swing bushes (27A, 27B) substantially make surface contact with the first annular piston (22) and the first blade (23). Then, the first annular piston (22) revolves while swinging relative to the first outer cylinder part (21a) and the first inner cylinder part (21b), and the first compression mechanism (20) performs a predetermined compression operation. Do.

  Specifically, in the first outer cylinder chamber (C1), the volume of the low-pressure chamber (C1-Lp) is almost the minimum in the state of FIG. 3 (B), and from here the drive shaft (33) rotates clockwise in the figure. When the volume of the low pressure chamber (C1-Lp) increases as it rotates and changes to the state of FIG. 3 (C) to FIG. 3 (A), the refrigerant flows into the suction pipe (14) and the suction port. It is sucked into the low pressure chamber (C1-Lp) through (41).

  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 first 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 predetermined value and the differential pressure from the discharge space (49) reaches a set value, the discharge valve is opened by the high-pressure refrigerant in the high-pressure chamber (C1-Hp), and 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 first inner cylinder chamber (C2), the volume of the low pressure chamber (C2-Lp) is almost the minimum in the state of FIG. 3 (F), and the drive shaft (33) rotates clockwise from here. When the volume of the low pressure chamber (C2-Lp) increases as the state changes from 3 (G) to FIG. 3 (E), the refrigerant flows into the suction pipe (14), the suction port (41), And through the through hole (44) to the low pressure chamber (C2-Lp) of the first inner cylinder chamber (C2).

  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. This 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 first 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 a set value, the discharge valve is opened by the high pressure refrigerant in the high pressure chamber (C2-Hp), and 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 first outer cylinder chamber (C1), refrigerant discharge is started approximately at the timing shown in FIG. 3E, and in the first 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 first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The high-pressure refrigerant compressed in the first outer cylinder chamber (C1) and the first 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 supplied to the refrigerant circuit. Then, after passing through the condensation stroke, 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 (70) of this comparative example is the first annular piston (22), whereas the example of FIGS. 1 to 3 is a movable bush type having the first annular piston (22) on the movable side. ) On the fixed side. In the following, differences from the example of FIGS. 1 to 3 will be mainly described.

  The first compression mechanism (20) and the second compression mechanism (50) are arranged between the front head (16) and the rear head (17) fixed to the casing (10), as in the example of FIGS. It is configured. The first compression mechanism (20) is disposed on the electric motor side (the upper side in FIG. 4), and the second compression mechanism (50) is disposed on the bottom (the lower side in FIG. 4) of the casing (10).

  The one compression mechanism (20) includes a first cylinder (21) having an annular first cylinder chamber (C1, C2), and a first annular piston (C1, C2) disposed in the first cylinder chamber (C1, C2). 22), the first cylinder chamber (C1, C2) is the first chamber, the high pressure chamber (compression chamber) (C1-Hp, C2-Hp) and the second chamber, the low pressure chamber (suction chamber) (C1-Lp , C2-Lp) and a first blade (23).

  On the other hand, the second compression mechanism (50) has the same configuration as the first compression mechanism (20) and is vertically inverted with respect to the first compression mechanism (20). The second compression mechanism (50) includes a second cylinder (51) having an annular second cylinder chamber (C3, C4), and a second annular piston disposed in the second cylinder chamber (C3, C4). (52) and a second blade (not shown) that divides the second cylinder chamber (C3, C4) into a high pressure chamber (not shown) as the first chamber and a low pressure chamber (not shown) as the second chamber. have.

  The first cylinder (21) is configured to perform eccentric rotational movement with respect to the first annular piston (22). That is, in this example, the first cylinder (21) having the first cylinder chamber (C1, C2) is the movable side, and the first annular piston (22) disposed in the first cylinder chamber (C1, C2) is provided. It is on the fixed side.

  On the other hand, the second cylinder (51) is configured to perform an eccentric rotational movement with respect to the second annular piston (52). That is, in this example, the second cylinder (51) having the second cylinder chamber (C3, C4) is the movable side, and the second annular piston (22) disposed in the second cylinder chamber (C3, C4) is provided. It is on the fixed side.

  The first cylinder (21) includes a first outer cylinder part (21a) and a first inner cylinder part (21b). The first outer cylinder portion (21a) and the first inner cylinder portion (21b) are integrated by connecting the lower end portions thereof with the first cylinder side end plate (21c). The first inner cylinder portion (21b) is slidably fitted into the first eccentric portion (33a) of the drive shaft (33).

  On the other hand, the second cylinder (51) includes a second outer cylinder part (51a) and a second inner cylinder part (51b). The second outer cylinder part (51a) and the second inner cylinder part (51b) are integrated by connecting the upper end part with the second cylinder side end plate (51c). The second inner cylinder part (51b) is slidably fitted into the second eccentric part (63a) of the drive shaft (33).

  In contrast, the first annular piston (22) is constituted by a front head (16), and the first annular piston body (22b) is formed integrally with the first piston side end plate (22c) at the upper end. It has a structure. On the other hand, the second annular piston (52) is constituted by a rear head (17), and the second annular piston main body (52b) is formed integrally with the second piston side end plate (52c) at the lower end. ing.

  A first outer cylinder chamber (C1) is formed between the first cylinder-side end plate (21c), the first piston-side end plate (22c), the first outer cylinder portion (21a), and the first annular piston body portion (22b). The first inner cylinder chamber (C2) between the first cylinder end plate (21c), the first piston end plate (22c), the first inner cylinder portion (21b), and the first annular piston main body portion (22b). Are formed in the same manner as in the example of FIGS.

  A second outer cylinder chamber (C3) is disposed between the second cylinder side end plate (51c), the second piston side end plate (52c), the second outer cylinder portion (51a), and the second annular piston main body portion (52b). Is formed, and a second inner cylinder chamber (51b) is formed between the second cylinder side end plate (51c), the second piston side end plate (52c), the second inner cylinder portion (51b), and the second annular piston main body portion (52b). The point C4) is formed is the same as in the example of FIGS.

  On the other hand, in this example, the front head (16) is provided with an operation space (26) for allowing the eccentric rotation of the first outer cylinder part (21a), and the rear head (17) is also provided with the second outer cylinder. An operation space (26) for allowing the eccentric rotation operation of the portion (51a) is formed. The operating space (26) is a low pressure space communicating with the suction pipe (14), and the first and second outer cylinder portions (21a, 51a) and the first and second inner cylinder portions (21b, 51b) have the low pressure space. Through holes (44a, 44b) for sucking low-pressure gas from the operation space (26) are respectively formed.

  Next, the internal structures of the first and second compression mechanisms (20, 50) will be described. Since they have the same configuration as described above, the first compression mechanism (20) will be described as a representative example.

  In this comparative example, in FIG. 5, the first swing bush (27A, 27B) has the first blade (23) in the surface direction with the first blade (23) sandwiched between the blade grooves (28). The blade groove (28) is configured to advance and retreat. The first swing bush (27A, 27B) is configured such that the first blade (23) swings with respect to the first annular piston (22). Therefore, in the first swing bush (27), the first blade (23) swings with respect to the first annular piston (22) with the center point of the first swing bush (27) as the swing center. The first blade (23) is configured to be able to advance and retreat in the surface direction of the first blade (23) with respect to the first annular piston (22).

  In the above configuration, when the drive shaft (33) rotates, the first outer cylinder portion (21a) and the first inner cylinder portion (21b) move while the first blade (23) advances and retreats in the blade groove (28). The first swing bush (27) swings about the center point. When the drive shaft (33) rotates, the second outer cylinder part (21a) and the second inner cylinder part (21b) are the same as the first outer cylinder part (21a) and the first inner cylinder part (21b). Further, the second blade (not shown) swings around the center point of the second swing bush (not shown) while moving back and forth in the second blade groove (not shown).

  By this swinging operation, the first contact point between the first annular piston (22) and the first cylinder (21) moves in order from FIG. 6 (A) to (H). On the other hand, the second contact point between the second annular piston (52) and the second cylinder (51) is shifted by 180 ° around the axis of the drive shaft (33) with respect to the first contact point. That is, when the operating state of the first compression mechanism (20) is FIG. 6 (A) when viewed from the upper side of the drive shaft (33), the operating state of the second compression mechanism (50) is FIG. 6 (E). .

  FIG. 6 is a view showing the operating state of the fixed bushing-type first compression mechanism (20), and the first cylinder (21) is shown at 45 ° intervals from FIG. 6 (A) to FIG. 6 (H). It shows a state of moving in the clockwise direction. At this time, the first outer cylinder portion (21a) and the first inner cylinder portion (21b) revolve while swinging around the drive shaft (33), but do not rotate. Other configurations are the same as those in the example of FIGS.

  Next, the operation of the compressor (1) will be described. Here, the operation of the first and second compression mechanisms (20, 50) is performed in a state of being shifted from each other by 180 °. Since the operations are the same except for the phase, the operation of the first compression mechanism (20) will be described as a representative.

  When the first compression mechanism (20) operates, in the first 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 (33) rotates clockwise in the figure and changes to the states of FIGS. 6 (G) to 6 (E), the refrigerant The suction pipe (14), the working space (26), and the through hole (44a) are sucked into the low pressure chamber (C1-Lp).

  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 first 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 predetermined value and the differential pressure from the discharge space (49) reaches a set value, the discharge valve is opened by the high-pressure refrigerant in the high-pressure chamber (C1-Hp), and 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 first inner cylinder chamber (C2), the volume of the low pressure chamber (C2-Lp) is almost the minimum in the state of FIG. 6B, and from here the drive shaft (33) rotates clockwise in the figure. When the volume of the low-pressure chamber (C2-Lp) increases as the state changes from 6 (C) to FIG. 6 (A), the refrigerant flows into the suction pipe (14), the operating space (26), It is sucked into the low pressure chamber (C2-Lp) through the through hole (44a), the low pressure chamber (C1-Lp) of the first outer cylinder chamber (C1), and the through hole (44b).

  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. This 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 first 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 a set value, the discharge valve is opened by the high pressure refrigerant in the high pressure chamber (C2-Hp), and 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 first outer cylinder chamber (C1), refrigerant discharge is started approximately at the timing of FIG. 6A, and in the first inner cylinder chamber (C2), discharge is started at approximately the timing of FIG. 6E. That is, the discharge timing differs by approximately 180 ° between the first outer cylinder chamber (C1) and the first inner cylinder chamber (C2). The high-pressure refrigerant compressed in the first outer cylinder chamber (C1) and the first 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 supplied to the refrigerant circuit. Then, after passing through the condensation stroke, the expansion stroke, and the evaporation stroke, it is sucked into the compressor (1) again.

-Explanation of rocking moment-
Next, the swinging moment generated in the compression mechanism will be described.

  The swing moment is a force acting on an object that swings like a pendulum with respect to a fulcrum, and is represented by the product of the moment of inertia around the fulcrum of the object and the swing angular acceleration. Further, the reaction force of this swinging moment acts on the fulcrum.

  FIG. 7 illustrates the swinging moment generated in the compression mechanism when the rotation angle (θ) of the drive shaft is 315 ° in the fixed bush system, and FIG. 8 illustrates the rotation angle ( The rocking moment generated in the compression mechanism when θ) is 315 ° is illustrated. Here, the rotation angle (θ) indicates a rotation angle around the drive shaft center (M2) in the drive shaft, and the swing angle (α) indicates a swing member (in the case of a fixed bush, a cylinder or a movable bush). In this case, the revolution angle around the fulcrum (M1) of the piston is shown. The fulcrum (M1) is at the center position of the swing bush (27). Further, the area of the area (A) indicated by hatching relatively indicates the swinging moment generated in the swinging member.

  In the case of the fixed bush type, as shown in FIG. 7, a swinging moment is generated in the cylinders (21, 51) that swing around the center position of the fixed swinging bush (27). Note that the reaction force of this swinging moment acts on the swinging bush (27) serving as the fulcrum (M1). The reaction force acting on the swing bush (27) is transmitted to the casing (10) to which the annular piston (22, 52) is fixed via the annular piston (22, 52), and the compressor (70 ).

  On the other hand, in the case of the movable bush system, as shown in FIG. 8, the annular piston (22, 52) that swings around the center position of the swing bush (27) that moves along the blade (23) is swung. A dynamic moment is generated. Note that the reaction force of this swinging moment acts on the swinging bush (27) serving as the fulcrum (M1). Then, the reaction force acting on the swing bush (27) is transmitted from the blade (23) to the casing (10) via the cylinders (21, 51), and the compressor (1) is vibrated.

  Next, the swinging moment when the compression mechanisms are arranged in two stages will be described.

  FIG. 9 shows the swinging moment in the fixed bush system. FIG. 9 (A) shows the first compression mechanism (20) arranged on the upper side, and FIG. 9 (B) shows the second compression mechanism arranged on the lower side. The rocking moments for (50) are shown. FIG. 10 shows the swinging moment in the movable bush system. FIG. 10 (A) shows the first compression mechanism (20) arranged on the upper side, and FIG. 10 (B) shows the second compression mechanism arranged on the lower side. The rocking moment in the case of the compression mechanism (50) is shown.

  In the case of the fixed bush system, as can be seen from FIG. 9, the area of the region (A) between the first compression mechanism (20) and the second compression mechanism (50), that is, swinging at an arbitrary rotation angle (θ). The moment may be different. Here, the area of the region (A) is different because the distance between the fulcrum (M1) and the cylinder center (M3) at an arbitrary rotation angle (θ) depends on the first compression mechanism (20) and the second compression mechanism ( This is because it differs from 50).

  On the other hand, in the case of the movable bush system, as can be seen from FIG. 10, the region (A) between the first compression mechanism (20) and the second compression mechanism (50) at an arbitrary rotation angle (θ). The area, that is, the rocking moment is the same. Here, the area of the region (A) is the same because the distance between the fulcrum (M1) and the center of the annular piston (M3) at an arbitrary rotation angle (θ) is the same as that of the first compression mechanism (20) and the second. This is because it is the same as the compression mechanism (50).

  FIG. 11 is a graph showing the relationship between the swinging moment and the rotation angle of the drive shaft in a compressor (70) in which fixed bush type compression mechanisms are arranged in two stages, and FIG. It is the graph which showed the relationship between the rocking | fluctuation moment and the rotation angle of a drive shaft in the compressor (1) which has arranged the compression mechanism of 2 steps | paragraphs. Note that the solid lines in FIGS. 11 and 12 indicate the swinging moments when the swinging moments of the compression mechanisms are overlapped.

  In the case of the fixed bush system, as described above, the swinging moment generated in the first compression mechanism (20) and the second compression mechanism (50) is different with respect to an arbitrary rotation angle (θ). Therefore, even if the compression mechanisms are arranged so that the respective operation operations are shifted by 180 °, the swing moments may not cancel each other, and the reaction force of the swing moment that cannot be canceled is transmitted to the compressor. .

  On the other hand, in the case of the movable bush method, as described above, the swinging moment generated in the first compression mechanism (20) and the second compression mechanism (50) is the same for an arbitrary rotation angle (θ). . That is, if the first compression mechanism (20) and the second compression mechanism (50) are configured by the same component, the magnitudes of the swinging moments of the compression mechanisms (20, 50) are equal. Therefore, if the compression mechanisms are arranged so that the respective operation operations are shifted by 180 °, the swing moments cancel each other, and as a result, the swing moment transmitted to the compressor (1) becomes zero.

-Effect of Embodiment 1-
According to the present embodiment, the first and second compression mechanisms (20, 50) are of a movable bush type, and the first eccentric portion (33a) and the second eccentric portion (63a) include the drive shaft (33). The first and second compression mechanisms (20, 50) have the same configuration (the same shape and the same dimensions) except that they are configured so that their phases are shifted from each other by 180.degree. The rocking moments generated in the two can cancel each other. Therefore, in the compressor (1), it is possible to reduce vibrations caused by the swing moments of the first and second compression mechanisms (20, 50).

  Even if the first compression mechanism (20) and the second compression mechanism (50) are not composed of the same components, the swinging moments of the compression mechanisms (20, 50) can be reduced by adopting the movable bush method. Since it acts in the direction of canceling out, it is possible to reduce the swinging moment of the compressor (1).

<< Embodiment 2 of the Invention >>
A second embodiment of the present invention will be described.

  Embodiment 2 uses a two-stage compression mechanism that uses carbon dioxide as the refrigerant (working fluid) of the compressor (1) and compresses the refrigerant in two stages by the first compression mechanism (20) and the second compression mechanism (50). This is a configured example.

  As shown in FIG. 13, the compressor (1) includes a movable bushing-type first compression mechanism (20) and a second compression mechanism (50), and the second compression mechanism (50) is a low-stage compression. The mechanism and the first compression mechanism (20) are high-stage compression mechanisms.

  The second compression mechanism (50) has a first suction pipe (14a) for sucking low-pressure refrigerant and a first discharge pipe (15a) for discharging intermediate-pressure refrigerant. The first suction pipe (14a) is fixed to the rear head (17) and communicates with the cylinder chambers (C3, C4) of the second compression mechanism (50). In the rear head (17), an intermediate discharge space (17b) communicating with the cylinder chambers (C3, C4) of the second compression mechanism (50) is formed. The intermediate pressure refrigerant compressed by the second compression mechanism (50) is discharged into the intermediate discharge space (17b) via the discharge port and a discharge valve (not shown). A first discharge pipe (15a) that passes through the body (11) of the casing (10) is fixed to the rear head (17), and the inner end of the first discharge pipe (15a) is at the rear head (17). Open to the intermediate discharge space (17b), and the outer end is connected to an intermediate pressure refrigerant pipe (not shown) of the refrigerant circuit.

  The first compression mechanism (20) has a second suction pipe (14b) for sucking in the intermediate pressure refrigerant. The second suction pipe (14b) is fixed to the front head (16) and communicates with the cylinder chambers (C1, C2) of the first compression mechanism (20). An injection pipe (14c) for injecting intermediate pressure refrigerant into the first compression mechanism (20) is connected to the second suction pipe (14b).

  The high-pressure refrigerant compressed in the cylinder chambers (C1, C2) of the first compression mechanism (20) is discharged to the discharge space (49) through the discharge port and the discharge valve (not shown), and this discharge space ( 49) to the high pressure space (19) in the casing (10). The high-pressure refrigerant filled in the casing (10) is discharged from the second discharge pipe (15b) provided in the upper part of the casing (10) to the high-pressure gas pipe of the refrigerant circuit.

  In the second embodiment, a two-stage compression mechanism is configured by the first compression mechanism (20) and the second compression mechanism (50), and the cylinder volume of the first compression mechanism (20) which is the higher stage side is lower. It is smaller than the cylinder volume of a certain second compression mechanism (50). Therefore, the axial length dimension L1 of the first annular piston body (22b) is smaller than the axial length dimension L2 of the second annular piston body (52b). On the other hand, the thickness dimension t1 of the first piston side end plate (22c) is larger than the thickness dimension t2 of the second piston side end plate (52c). By doing so, the magnitude of the swing moment generated in the first compression mechanism (20) is made equal to the magnitude of the swing moment generated in the second compression mechanism (50).

  The swing moment is a value proportional to the moment of inertia of the piston × e (the amount of eccentricity in FIG. 8) / L (the distance between the fulcrum (M1) and the center of the annular piston (M3) in FIG. 8). When the inertia moments of the piston main body portions of the first compression mechanism (20) and the second compression mechanism (50) are different, the swing moment can be adjusted by adjusting the inertia moment, e dimension, and L dimension of the piston end plate portion. it can.

  In the second embodiment, the first eccentric portion (33a) and the second eccentric portion (63a) are configured to be 180 ° out of phase with each other about the axis of the drive shaft (33). Other configurations are the same as those of the first embodiment.

  According to this embodiment, in the two-stage compression mechanism in which the cylinder volumes of the first compression mechanism (20) and the second compression mechanism (50) are different, the axial length of the first annular piston body (22b) is set to the first dimension. By making the thickness dimension of the first piston-side end plate (22c) larger than the thickness dimension of the second piston-side end plate (52c), while making it shorter than the axial length of the two annular piston body (52b) The swing moment is matched by the first compression mechanism (20) and the second compression mechanism (50). For this reason, the first eccentric portion (33a) and the second eccentric portion (63a) are coupled with the 180 ° phase shift from each other about the axis of the drive shaft (33), and thus the oscillation generated in each compression mechanism. Moments cancel each other out. Therefore, in the two-stage compression compressor (1) using carbon dioxide as a refrigerant, vibrations caused by the swing moments of the first and second compression mechanisms (20, 50) can be reduced.

  In the second embodiment, the axial length of the first annular piston body (22b) is made smaller than the axial length of the second annular piston body (52b), whereby the first compression mechanism (20 ) And the second compression mechanism (50) are made to have different cylinder volumes, but the cylinder volume is adjusted by the diameter of the first annular piston body (22b) and the second annular piston body (52b). May be.

  In the second embodiment, a two-stage compression mechanism is employed in which the cylinder volume of the first compression mechanism (20) is smaller than the cylinder volume of the second compression mechanism (50), but the injection amount of the intermediate pressure refrigerant is increased. Thus, the cylinder volume of the first compression mechanism (20) becomes the same as the cylinder volume of the second compression mechanism (50), or the cylinder volume of the first compression mechanism (20) is the cylinder of the second compression mechanism (50). It is also possible to make the configuration larger than the volume. When the cylinder volumes of both compression mechanisms (20, 50) are the same, it is sufficient to use parts having the same configuration (the same shape and the same dimensions) for each compression mechanism (20, 50), and the cylinder volume of the first compression mechanism (20). Is larger than the cylinder volume of the second compression mechanism (50), contrary to the above, the axial length of the first annular piston body (22b) is set to the axial direction of the second annular piston body (52b). While making it longer than the length dimension, the thickness dimension of the first piston side end plate (22c) may be smaller than the thickness dimension of the second piston side end plate (52c).

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

  In the above embodiment, the eccentric rotary piston mechanism is configured by a compression mechanism, but is not limited thereto, and may be configured by, for example, an expansion mechanism.

  In the above embodiment, the first eccentric part (33a) and the second eccentric part (63a) are 180 ° out of phase with each other about the axis of the drive shaft (33). The phase difference is not limited and may be a phase difference range advantageous for the fixed bush system, for example, 180 ± 15 °.

  In the first embodiment, the first and second compression mechanisms (20, 50) have the same configuration except that the first eccentric portion (33a) and the second eccentric portion (63a) have a phase difference. (In other words, the shape ratio of the second annular piston (52) to the first annular piston (22) is 1). However, the shape ratio is not limited to this, and the shape ratio is within a range advantageous for the fixed bushing system. May be changed. In changing the shape ratio, the moment of inertia ratio or e (the eccentric amount in FIG. 8) / L (the distance between the fulcrum (M1) in FIG. 8 and the center of the annular piston (M3)) is changed. Preferably, the moment of inertia ratio and the e / L ratio are each changed in the range of 0.74 to 1.26.

  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, the present invention provides a rotary fluid machine in which an eccentric rotary piston mechanism having a cylinder having an annular cylinder chamber and an annular piston housed eccentrically in the cylinder chamber is arranged in two stages. Useful for.

It is a longitudinal section of the compressor concerning Embodiment 1 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 rocking | fluctuation moment which generate | occur | produces in the compression mechanism which concerns on a comparative example. FIG. 4 is a diagram illustrating a swinging moment generated in the compression mechanism according to the first embodiment. It is a figure which shows the rocking | fluctuation moment which generate | occur | produces in the 1st, 2nd compression mechanism which concerns on a comparative example. It is a figure which shows the rocking | fluctuation moment which generate | occur | produces in the 1st, 2nd compression mechanism which concerns on Embodiment 1. FIG. It is a graph which shows the rocking | fluctuation moment which generate | occur | produces in the compression mechanism which concerns on a comparative example. 6 is a graph showing a swinging moment generated in the compression mechanism according to the first embodiment. It is a longitudinal cross-sectional view of the compressor which concerns on Embodiment 2. FIG.

Explanation of symbols

1 Compressor (rotary fluid machine)
10 Casing
14 Suction pipe
15 Discharge pipe
20 First compression mechanism (first eccentric rotary piston mechanism)
21 1st cylinder
21a First outer cylinder
21b First inner cylinder
21c End plate on the first cylinder side
22 First annular piston
22a First bearing
22b First annular piston body
22c End plate on the first piston side
23 First blade
27 First swing bush
30 Electric motor (drive mechanism)
33 Drive shaft
33a First eccentric part
50 Second compression mechanism (second eccentric rotating piston mechanism)
51 2nd cylinder
51a Second outer cylinder
51b Second inner cylinder
51c End plate on the second cylinder side
52 Second annular piston
52a Second bearing
52b Second annular piston body
52c End plate on the second piston side
63a Second eccentric part
C1 1st outer cylinder chamber
C2 1st inner cylinder chamber
C3 Second outer cylinder chamber
C4 Second inner cylinder chamber
C1-Hp High pressure chamber
C2-Hp High pressure chamber
C1-Lp Low pressure chamber
C2-Lp Low pressure chamber

Claims (8)

A first eccentric rotary piston mechanism (20) and a second eccentric rotary piston mechanism (50) arranged in two stages, and a drive shaft (33) for driving the eccentric rotary piston mechanisms (20, 50). And a drive mechanism (30) having
Each eccentric rotary piston mechanism (20, 50) has a cylinder (21, 51) having an annular cylinder chamber (C1, C2, C3, C4) and the cylinder chamber (C1, C2, C3, C4) outside. An annular piston (22, 52) housed eccentrically in the cylinder chamber (C1, C2, C3, C4) so as to be divided into a cylinder chamber (C1, C3) and an inner cylinder chamber (C2, C4), and each cylinder A rotary fluid machine having a blade (23) that divides a chamber (C1, C2, C3, C4) into a first chamber and a second chamber,
The annular piston (22, 52) is configured to perform eccentric rotational movement with respect to the cylinder (21, 51),
The swing moment generated by the eccentric rotation operation of the first eccentric rotary piston mechanism (20) and the swing moment generated by the eccentric rotation operation of the second eccentric rotary piston mechanism (50) cancel each other. A rotary fluid machine in which both piston mechanisms (20, 50) are arranged so as to have a phase difference. In claim 1,
The phase difference between the swing moment generated by the first eccentric rotary piston mechanism (20) and the swing moment generated by the second eccentric rotary piston mechanism (50) is set to 180 °. Rotary fluid machine. In claim 1 or 2,
The rotary fluid machine according to claim 1, wherein the first eccentric rotary piston mechanism (20) and the second eccentric rotary piston mechanism (50) have equal swinging moments. In claim 1, 2 or 3,
The annular pistons (22, 52) of the first eccentric rotating piston mechanism (20) and the second eccentric rotating piston mechanism (50) are respectively an annular piston body (22b, 52b) and the annular piston body. (22b, 52b) having a piston side end plate (22c, 52c) formed at the axial end portion,
One of the eccentric rotary piston mechanisms is a rotary fluid machine characterized in that when the axial length of the annular piston main body is smaller than the other, the thickness of the piston side end plate is larger than the other. In claim 1, 2 or 3,
A rotary fluid machine, wherein the first eccentric rotary piston mechanism (20) and the second eccentric rotary piston mechanism (50) are configured using the same components. In any one of claims 1 to 5,
A rotary fluid machine, wherein the first eccentric rotary piston mechanism (20) and the second eccentric rotary piston mechanism (50) are compression mechanisms. In claim 6,
A rotary fluid machine, wherein the first eccentric rotary piston mechanism (20) and the second eccentric rotary piston mechanism (50) constitute a two-stage compression mechanism that compresses the working fluid in two stages. In claim 6 or 7,
A rotary fluid machine, wherein the working fluid is carbon dioxide.

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