JP2019039418A - Rotary compressor - Google Patents

Abstract

To contract the difference of oscillation moment between two piston members, to reduce oscillation of a rotary compressor.SOLUTION: Two piston members (40, 45) provided in a rotary compressor respectively comprise cylindrical piston bodies (41, 46) and planar blades (42, 47). The respective piston bodies (41, 46) have the same outer diameter. On a drive shaft, an outer diameter of a lower eccentric part to which the lower piston body (46) is fitted, is smaller than an outer diameter of an upper eccentric part to which the upper piston body (41) is fitted. A mass of the first blade (42) of the first piston member (40) is heavier than a mass of the second blade (47) of the second piston member (45).SELECTED DRAWING: Figure 5

Description

  The present invention relates to a two-cylinder rotary compressor.

  2. Description of the Related Art Conventionally, an oscillating piston type rotary compressor including a piston member in which a cylindrical piston body and a flat blade are integrally formed is known. Patent Document 1 discloses a rocking piston type rotary compressor provided with two sets of a cylinder and a piston member. In this rotary compressor, the eccentric portion of the drive shaft is inserted through the piston body of each piston member. Then, when the drive shaft is rotationally driven by the electric motor, the piston member performs a swinging motion in the cylinder in a state where the blade is supported so as to be rotatable and advanceable / retractable with respect to the cylinder.

  Patent Document 2 discloses a rotary compressor including two sets of a cylinder that forms an annular cylinder chamber and an annular piston that is accommodated in the cylinder chamber. In this rotary compressor, the cylinder and the annular piston relatively rotate eccentrically. And this patent document 2 describes arranging each set of cylinders and annular pistons so that the swinging moments caused by the relative eccentric rotational movements of each set of cylinders and annular pistons cancel each other. ing.

Japanese Patent Laying-Open No. 2015-197044 JP 2009-085216 A

  As described above, in the oscillating piston type rotary compressor, the piston member oscillates in the cylinder while the blade is supported so as to be rotatable and advanceable / retractable with respect to the cylinder. That is, the piston member driven by the drive shaft swings around the eccentric portion of the drive shaft while revolving in the cylinder. The central axis of the piston main body of the piston member substantially coincides with the central axis of the eccentric portion of the drive shaft. Therefore, the piston member rotates so as to reciprocate within a predetermined angular range around the central axis of the piston body.

  The swing moment of the piston member is the product of “moment of inertia about the central axis of the piston body” and “swing angular acceleration of the piston member”. The swing moment generated by the swing motion of the piston member causes vibration of the rotary compressor. In the present specification, “the swinging moment of the piston member” means “the moment of inertia of the piston member around the central axis of the piston body” unless otherwise specified.

  In the two-cylinder rotary compressor as disclosed in Patent Document 1, when the shapes of the two piston members are the same, the moments of inertia of both coincide. Therefore, in this case, since the swing moments of the two piston members almost cancel each other, the swing moments of the piston members do not significantly affect the vibration of the rotary compressor.

  On the other hand, in a two-cylinder rotary compressor as disclosed in Patent Document 1, when the piston bodies of the two piston members have different thicknesses, the two piston members are swung to suppress vibration of the rotary compressor. It is necessary to make the difference in dynamic moment as small as possible.

  For example, it is assumed that the thickness of the second piston body of the second piston member is thicker than the thickness of the first piston body of the first piston member. In this case, in order to reduce the difference between the swinging moments of the piston members, it may be possible to reduce the difference in mass between the two piston members by forming a thinning groove in the second piston body. However, the second piston body is close to the central axis of the second piston body. For this reason, in order to sufficiently reduce the moment of inertia of the second piston member, it is necessary to form a large groove in the second piston body, and the rigidity of the second piston body is insufficient to impair the reliability of the rotary compressor. There is a fear.

  The present invention has been made in view of the above points, and an object of the present invention is to reduce the difference in the swing moment of each piston member in a swing piston type rotary compressor having two piston members having different shapes. This is to reduce the vibration of the rotary compressor.

  The first invention is the first cylinder (30) and the second cylinder (35), the first piston member (40) accommodated in the first cylinder (30), and the second cylinder (35). A rotary compressor including a second piston member (45) to be driven and a drive shaft (70) for driving the first piston member (40) and the second piston member (45) is an object. The first piston member (40) includes a cylindrical first piston body (41) and a flat plate that is integral with the first piston body (41) and extends outward from the first piston body (41). And the second piston member (45) is integral with the cylindrical second piston main body (46) and the second piston main body (46) and the second piston body (46). A flat plate-like second blade (47) extending outward from the piston body (46), and the drive shaft (70) is eccentric with respect to the rotation center axis (70a) of the drive shaft (70). A first eccentric part (75) formed in a columnar shape and fitted with the first piston body (41), and a columnar shape eccentric with respect to the rotation center axis (70a) of the drive shaft (70). A second eccentric portion (76) into which the second piston main body (46) is fitted, and the drive shaft (70) includes the first eccentric portion (75). The amount of eccentricity is equal to the amount of eccentricity of the second eccentric portion (76), the outer diameter of the first eccentric portion (75) is larger than the outer diameter of the second eccentric portion (76), and the first piston body ( The outer diameter of 41) is equal to the outer diameter of the second piston body (46), and the mass of the first blade (42) is larger than the mass of the second blade (47).

In the first invention, the first piston member (40) includes the first piston body (41) and the first blade (42), and the second piston member (45) includes the second piston body (46) and the second piston body (46). A blade (47). In the drive shaft (70), the outer diameter φD _{e1 of} the first eccentric portion (75) is larger than the outer diameter φD _{e2 of} the second eccentric portion (76) (φD _e1 > φD _e2 ). The first piston body (41) of the first piston member (40) is fitted into the first eccentric part (75), and the second piston body (2) of the second piston member (45) is fitted into the second eccentric part (76). 46) fits. Accordingly, the inner diameter [phi] D _pi1 of the first piston body (41) is larger than the inner diameter [phi] D _pi2 of the second piston body _{(46) (φD pi1> φD} pi2). On the other hand, the outer diameter [phi] D _po1 of the first piston body (41) is equal to the outer diameter [phi] D _po2 of the second piston body _{(46) (φD po1 = φD} po2). Therefore, the thickness of the first piston body _{(41) ((φD po1 -φD} pi1) / 2) is thinner than the thickness of the second piston body _{(46) ((φD po2 -φD} pi2) / 2) Become. In the present invention, the mass M _{b1 of} the first blade (42) is larger than the mass M _{b2 of} the second blade (47) (M _b1 > M _b2 ).

  In the piston member (40, 45), the blade (42, 47) is farther from the center axis (41a, 46a) of the piston body (41, 46) than the piston body (41, 46). For this reason, if the mass change amount is the same, the moment of inertia of the piston member (more precisely, the moment of inertia of the piston member (40, 45) around the central axis (41a, 46a) of the piston body (41, 46)) ) Is larger when the mass of the blade (42, 47) is changed than when the mass of the piston body (41, 46) is changed.

  Therefore, in the first invention, the mass of the first blade (42) of the first piston member (40) having the first piston main body (41) having a relatively thin thickness is set to be relatively large. It is larger than the mass of the second blade (47) of the second piston member (45) having the two-piston body (46). For this reason, the moment of inertia of the first piston member (40) and the second piston member (45) is suppressed while keeping the increase in the mass of the first blade (42) or the reduction in the mass of the second blade (47) small. The difference can be reduced.

  In a second aspect based on the first aspect, the first blade (42) has one or both of length and thickness longer than the second blade (47).

  In the second aspect of the invention, one or both of the length and thickness of the first blade (42) is set to the second blade (42) so that the mass of the first blade (42) is larger than the mass of the second blade (47). 47) is longer.

  In a third aspect based on the first aspect, the first blade (42) has a length longer than that of the second blade (47) and a thickness of the second blade (47). Is the same.

  In the third invention, the thickness of the first blade (42) is made equal to the thickness of the second blade (47), and the mass of the first blade (42) is larger than the mass of the second blade (47). Thus, the length of the first blade (42) is made longer than the length of the second blade (47).

  When the length of the blade (42, 47) is increased, the region on the tip side becomes longer than the portion of the blade (42, 47) supported by the cylinder (30, 35). On the other hand, an external force does not act on the region of the blade (42, 47) on the tip side of the portion supported by the cylinder (30, 35). That is, the shape of the region of the blade (42, 47) on the tip side of the portion supported by the cylinder (30, 35) has no influence on the function of the blade (42, 47). Therefore, in the third invention, the length of the first blade (42) is made longer than the length of the second blade (47), so that the function of the first blade (42) is not affected. The mass of one blade (42) is made larger than the mass of the second blade (47).

  In a fourth aspect based on any one of the first to third aspects, the material of the first piston member (40) is the same as the material of the second piston member (45).

  In the fourth invention, the first piston member (40) and the second piston member (45) are made of the same material.

  According to a fifth invention, in any one of the first to fourth inventions, the first piston member (40) has an inertia moment relative to a moment of inertia of the first piston member (40) around the central axis (41a) of the first piston body (41). The ratio of the moment of inertia of the second piston member (45) around the central axis (46a) of the two-piston body (46) is 1 or more and the second piston member (to the mass of the first piston member (40)) It is smaller than the mass ratio of 45).

In the fifth invention, “the central axis (46a) of the second piston body (46) with respect to the inertia moment I ₁ of the first piston member (40) around the central axis (41a) of the first piston body (41)”. The ratio (I ₂ / I ₁ ) of the inertia moment I ₂ ”of the second piston member (45) around ₁ is 1 or more, and the“ second piston member (to the mass M _{1 of} the first piston member (40) ”( 45), which is smaller than the mass M ₂ ratio (M ₂ / M ₁ ) ”(1 ≦ I ₂ / I ₁ <M ₂ / M ₁ ).

  In the present invention, the mass of the first blade (42) of the first piston member (40) having the first piston body (41) having a relatively thin thickness is set to the second piston body ( The mass of the second blade (47) of the second piston member (45) having 46) is larger. For this reason, the difference of the moment of inertia of the 1st piston member (40) and the 2nd piston member (45) can be reduced, suppressing the amount of change of the mass of the 1st blade (42) or the 2nd blade (47) small. If the difference in inertia moment between the two piston members (40, 45) is reduced, the difference in swinging moment between the two piston members (40, 45) is reduced.

  Thus, according to the present invention, in the rotary compressor (1) having two piston members (40, 45) having different shapes, the mass of the first blade (42) or the second blade (47) is changed. The difference in swing moment between the two piston members (40, 45) can be reduced while keeping the amount small. Therefore, according to the present invention, while the reliability of the rotary compressor (1) is ensured by suppressing changes in the configuration (for example, shape and material) of each blade (42, 47), the rotary compressor ( 1) Vibration can be suppressed.

  In the third invention, the thickness of the first blade (42) is the same as the thickness of the second blade (47), and the mass of the first blade (42) is greater than the mass of the second blade (47). So that the length of the first blade (42) is longer than the length of the second blade (47). Therefore, according to this invention, the mass of the first blade (42) is made larger than the mass of the second blade (47) without affecting the function of the first blade (42), and the two piston members are made. Can reduce the difference between the swing moments of (40, 45).

FIG. 1 is a longitudinal sectional view of the rotary compressor according to the first embodiment. FIG. 2 is a longitudinal sectional view of the compression mechanism of the first embodiment. FIG. 3 is a cross-sectional view of the compression mechanism showing a III-III cross section in FIG. 2. 4 is a cross-sectional view of the compression mechanism showing a cross section taken along line IV-IV in FIG. FIG. 5 is a plan view of the upper piston member and the lower piston member of the first embodiment. FIG. 6 is a plan view of a cylinder (an upper cylinder or a lower cylinder) according to the first embodiment. It is the figure which put in order and showed the cross section of the compression mechanism shown in FIG.3 and FIG.4 in case the rotation angle of a drive shaft is every 90 degrees. FIG. 8 is a plan view of the upper piston member and the lower piston member of the second embodiment.

  Embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments and modifications described below are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

Embodiment 1
The first embodiment will be described. The compressor of the present embodiment is a so-called oscillating piston type rotary compressor (1). The rotary compressor (1) is provided in a refrigerant circuit that performs a vapor compression refrigeration cycle, and sucks and compresses refrigerant evaporated by an evaporator.

-Overall configuration of rotary compressor-
As shown in FIG. 1, the rotary compressor (1) of this embodiment is a hermetic compressor. In the rotary compressor (1), the compression mechanism (15) and the electric motor (10) are accommodated in the casing (2).

  The casing (2) is a cylindrical sealed container in an upright state. The casing (2) includes a cylindrical body (3) and a pair of end plates (4, 5) that close the end of the body (3). A suction pipe (7, 8) is attached to the lower part of the body (3). A discharge pipe (6) is attached to the upper end plate (4).

  The electric motor (10) is disposed in the upper part of the internal space of the casing (2). The electric motor (10) includes a stator (11) and a rotor (12). The stator (11) is fixed to the body (3) of the casing (2). The rotor (12) is attached to a drive shaft (70) of a compression mechanism (15) described later.

  The compression mechanism (15) is a so-called oscillating piston type rotary fluid machine. In the internal space of the casing (2), the compression mechanism (15) is disposed below the electric motor (10).

-Compression mechanism-
As shown in FIG. 2, the compression mechanism (15) is a two-cylinder rotary fluid machine. The compression mechanism (15) includes one front head (20), one rear head (25), and one drive shaft (70). The compression mechanism (15) includes two cylinders (30, 35) and two piston members (40, 45). Each cylinder (30, 35) is provided with a pair of two bushes (43, 48) in pairs. The compression mechanism (15) includes an intermediate plate (50). The intermediate plate (50) includes a first plate member (60) and a second plate member (65).

  In the compression mechanism (15), the rear head (25), the lower cylinder (35), the intermediate plate (50), the upper cylinder (30), and the front head (20) are arranged in order from the bottom to the top. It is arranged in an overlapping state. The rear head (25), the lower cylinder (35), the intermediate plate (50), the upper cylinder (30), and the front head (20) are fastened together by a plurality of bolts (not shown). In the compression mechanism (15), the front head (20) is fixed to the body (3) of the casing (2).

<Upper cylinder, lower cylinder>
As shown in FIGS. 2 to 4, each cylinder (30, 35) is a thick disk-shaped member. The upper cylinder (30) constitutes a first cylinder, and the lower cylinder (35) constitutes a second cylinder.

  Each cylinder (30, 35) is formed with a cylinder bore (31, 36), a blade accommodation hole (32, 37), and a suction port (33, 38). The upper cylinder (30) and the lower cylinder (35) have the same thickness. Although not shown in FIGS. 3 and 4, the cylinders (30, 35) such as through holes for inserting bolts for assembling the compression mechanism (15) are inserted into the cylinders (30, 35). ) In the thickness direction are formed.

The cylinder bore (31, 36) is a circular hole that penetrates the cylinder (30, 35) in the thickness direction, and is formed at the center of the cylinder (30, 35). The wall surface of the cylinder bore (31, 36) is a cylindrical surface. The upper piston body (41) of the upper piston member (40) is accommodated in the cylinder bore (31) of the upper cylinder (30). The lower piston body (46) of the lower piston member (45) is accommodated in the cylinder bore (36) of the lower cylinder (35). The inner diameter φD _C1 of the cylinder bore (31) of the upper cylinder (30) and the inner diameter of the cylinder bore (36) of the second cylinder (35) and φD _C2 are equal to each other.

  In the upper cylinder (30), an upper fluid chamber (34) that is a first fluid chamber is formed between the wall surface of the cylinder bore (31) and an upper piston body (41) of an upper piston member (40) described later. The The upper cylinder (30) forms an upper fluid chamber (34) together with the upper piston body (41). In the lower cylinder (35), a lower fluid chamber which is a second fluid chamber is provided between the wall surface of the cylinder bore (36) and a lower piston body (46) of a lower piston member (45) described later. (39) is formed. The lower cylinder (35) forms a lower fluid chamber (39) together with the lower piston body (46).

  The blade accommodation hole (32, 37) is a hole extending from the inner peripheral surface of the cylinder (30, 35) (that is, the wall surface of the cylinder bore (31, 36)) to the outside in the radial direction of the cylinder (30, 35). is there. The blade accommodation holes (32, 37) penetrate the cylinders (30, 35) in the thickness direction. The upper blade (42) is accommodated in the blade accommodation hole (32) of the upper cylinder (30). The lower blade (47) is accommodated in the blade accommodation hole (37) of the lower cylinder (35). The blade accommodation holes (32, 37) are shaped so that their wall surfaces do not interfere with the oscillating blades (42, 47).

As shown in FIG. 6, the blade accommodating holes (32, 37) of the respective cylinders (30, 35) are formed with bush accommodating portions (32a, 37a) near the cylinder bores (31, 36). The bush accommodating portions (32a, 37a) are concave portions opened in the wall surface of the blade accommodating hole (32, 37), and are formed one on each of the right side surface and the left side surface of the blade accommodating hole (32, 37) in FIG. Has been. In the upper cylinder (30), the wall surface of the bushing accommodation portion (32a) is the center of curvature axis (32 b) there is and the radius of curvature r _b in common is equal cylindrical surface. In the lower cylinder (35), the wall surface of the bushing accommodation portion (37a) is the center of curvature axis (37b) there is and the radius of curvature r _b in common is equal cylindrical surface.

  The suction port (33, 38) is a hole having a circular cross section extending from the wall surface of the cylinder bore (31, 36) toward the outside in the radial direction of the cylinder (30, 35). The suction port (33, 38) is disposed in the vicinity of the blade accommodation hole (32, 37) (in this embodiment, right next to the blade accommodation hole (32, 37) in FIGS. 3 and 4), and the cylinder ( 30,35). The upper suction pipe (7) is inserted into the suction port (33) of the upper cylinder (30), and the lower suction pipe (8) is inserted into the suction port (38) of the lower cylinder (35) (see FIG. 1).

<Front head>
The front head (20) is a member that closes the end surface (upper end surface in FIG. 2) of the upper cylinder (30) on the electric motor (10) side. The front head (20) includes a main body portion (21), a main bearing portion (22), and an outer peripheral wall portion (23).

  The main body (21) is formed in a generally circular thick plate shape. The main body (21) is disposed so as to cover the end surface of the upper cylinder (30). The front surface (lower surface in FIG. 2) of the main body (21) is in close contact with the upper cylinder (30). The main bearing portion (22) is formed in a cylindrical shape extending from the main body portion (21) to the electric motor (10) side (upper side in FIG. 1), and is disposed at the central portion of the main body portion (21). The main bearing portion (22) constitutes a journal bearing that supports the drive shaft (70) of the compression mechanism (15). The outer peripheral wall portion (23) is a thick annular portion formed continuously from the outer peripheral edge portion of the main body portion (21).

  A discharge port (24) is formed in the front head (20). The discharge port (24) penetrates the main body (21) of the front head (20) in the thickness direction. As shown in FIG. 3, on the front surface of the main body (21) of the front head (20) (the surface in contact with the upper cylinder (30)), the discharge port (24) is connected to the blade accommodation hole (32) of the upper cylinder (30). ) In the vicinity of the side opposite to the suction port (33) (in this embodiment, the left side of the blade accommodation hole (32) in FIG. 3). Moreover, although not shown in figure, the discharge valve for opening and closing a discharge port (24) is attached to the main-body part (21) of a front head (20).

<Rear head>
The rear head (25) is a member that closes the end surface (the lower end surface in FIG. 1) opposite to the electric motor (10) of the lower cylinder (35). The rear head (25) includes a main body portion (26), a sub bearing portion (27), and an outer peripheral wall portion (28).

  The main body (26) is formed in a substantially circular thick plate shape. The main body (26) is disposed so as to cover the end surface of the lower cylinder (35). The front surface (upper surface in FIG. 2) of the main body (26) is in close contact with the lower cylinder (35). The sub bearing portion (27) is formed in a cylindrical shape extending from the main body portion (26) to the opposite side (lower side in FIG. 2) of the lower cylinder (35), and is arranged at the center of the main body portion (26). The The auxiliary bearing portion (27) constitutes a journal bearing that supports the drive shaft (70) of the compression mechanism (15). The outer peripheral wall portion (28) is formed in a cylindrical shape extending from the outer peripheral edge portion of the main body portion (26) to the opposite side of the lower cylinder (35). The length (height) of the outer peripheral wall portion (28) is substantially equal to the length (height) of the auxiliary bearing portion (27).

  A discharge port (29) is formed in the rear head (25). The discharge port (29) penetrates the main body (26) of the rear head (25) in the thickness direction. As shown in FIG. 4, on the front surface of the main body (26) of the rear head (25) (the surface in contact with the lower cylinder (35)), the discharge port (29) is connected to the blade receiving hole ( 37) in the vicinity of the side opposite to the suction port (38) (in the present embodiment, the left side of the blade accommodation hole (37) in FIG. 4). Moreover, although not shown in figure, the discharge valve for opening and closing a discharge port (29) is attached to the main-body part (26) of a rear head (25).

<Intermediate plate>
As described above, the intermediate plate (50) is constituted by the first plate member (60) and the second plate member (65). The first plate member (60) and the second plate member (65) are disk-shaped members. A through hole for inserting the drive shaft (70) is formed at the center of each plate member (60, 65).

  The first plate member (60) and the second plate member (65) constitute an intermediate plate (50) by overlapping each other. The first plate member (60) is disposed on the upper cylinder (30) side and covers the end surface (the lower surface in FIG. 2) of the upper cylinder (30). The second plate member (65) is disposed on the lower cylinder (35) side and covers the end surface (the upper surface in FIG. 2) of the lower cylinder (35).

<Drive shaft>
As shown in FIGS. 1 and 2, the drive shaft (70) includes a main shaft portion (72), an upper eccentric portion (75), an intermediate connecting portion (80), a lower eccentric portion (76), The side connection part (90) and the countershaft part (74) are provided. The drive shaft (70) is arranged such that its rotation center axis (70a) substantially coincides with the center axis of the cylinder bore (31, 36) of each cylinder (30, 35).

  In the drive shaft (70), the main shaft portion (72), the upper eccentric portion (75), the intermediate connecting portion (80), the lower eccentric portion (76), the lower connecting portion (90), and the countershaft The parts (74) are arranged in order from top to bottom. In the drive shaft (70), the main shaft portion (72), the upper eccentric portion (75), the intermediate connecting portion (80), the lower eccentric portion (76), the lower connecting portion (90), and the countershaft The part (74) is formed integrally with each other.

  The main shaft portion (72) is a columnar or rod-shaped portion having a circular cross section. The rotor (12) of the electric motor (10) is attached to the upper part of the main shaft part (72). The lower part of the main shaft part (72) constitutes a journal supported by the main bearing part (22) of the front head (20). The auxiliary shaft portion (74) is a columnar or rod-shaped portion having a circular cross section. The auxiliary shaft part (74) constitutes a journal supported by the auxiliary bearing part (27) of the rear head (25). The center axis of the main shaft portion (72) and the center axis of the sub shaft portion (74) coincide with the rotation center axis (70a) of the drive shaft (70).

  Each eccentric part (75,76) is a cylindrical part having a larger diameter than the main shaft part (72). The upper eccentric part (75) constitutes a first eccentric part, and the lower eccentric part (76) constitutes a second eccentric part. In each of the eccentric portions (75, 76), the center axis (75a, 76a) is eccentric with respect to the rotation center axis (70a) of the drive shaft (70).

  The upper eccentric part (75) is eccentric to the opposite side of the lower eccentric part (76) with respect to the rotation center axis (70a) of the drive shaft (70). That is, the eccentric direction of the upper eccentric portion (75) with respect to the rotation center axis (70a) of the drive shaft (70) is the eccentric direction of the lower eccentric portion (76) with respect to the rotation center axis (70a) of the drive shaft (70). 180 ° different.

The upper eccentric portion and the eccentricity _{e 1} (75), the eccentricity _{e 2} of the lower eccentric portion (76) are equal to each other _(e 1 _{= e} 2). The eccentricity e ₁ of the upper eccentric part (75) is the distance between the central axis (75a) of the upper eccentric part (75) and the rotation central axis (70a) of the drive shaft (70). Further, the eccentricity e ₂ of the lower eccentric portion (76) is the distance of the lower eccentric portion central axis of (76) (76a) and the axis of rotation of the drive shaft (70) and (70a).

The outer diameter φD _e2 of the lower eccentric portion (76) is smaller than the outer diameter φD _e1 of the upper eccentric portion (75) (φD _e2 <φD _e1 ). The upper eccentric portion (75) and the lower eccentric portion (76) have substantially the same height (that is, the length of the drive shaft (70) in the rotation center axis (70a) direction). The height of the upper eccentric part (75) is slightly lower than the height H _p1 of the upper piston body (41), and the height of the lower eccentric part (76) is the height of the lower piston body (46). Slightly lower than _Hp2 .

  The intermediate connecting portion (80) is disposed between the upper eccentric portion (75) and the lower eccentric portion (76), and connects the upper eccentric portion (75) and the lower eccentric portion (76). The lower connecting portion (90) is disposed between the lower eccentric portion (76) and the auxiliary shaft portion (74), and connects the lower eccentric portion (76) and the auxiliary shaft portion (74).

  An oil supply passage (71) is formed in the drive shaft (70). The lubricating oil collected at the bottom of the casing (2) is supplied to the bearing of the drive shaft (70) and the sliding portion of the compression mechanism (15) through the oil supply passage (71). 3, 4, and 7, the illustration of the oil supply passage (71) is omitted.

<Upper piston member, lower piston member>
As shown in FIG. 5, the upper piston member (40) includes an upper piston body (41) and an upper blade (42). The lower piston member (45) includes a lower piston body (46) and a lower blade (47). The material of the upper piston member (40) is the same as the material of the lower piston member (45).

  The upper piston member (40) constitutes a first piston member, the upper piston body (41) constitutes a first piston body, and the upper blade (42) constitutes a first blade. The lower piston member (45) constitutes a second piston member, the lower piston body (46) constitutes a second piston body, and the lower blade (47) constitutes a second blade.

  Each piston body (41, 46) is a part formed in a slightly thick cylindrical shape. The outer surface and the inner surface of each piston body (41, 46) are both cylindrical surfaces with the central axis (41a, 46a) of the piston body (41, 46) as the central axis of curvature. However, the outer surface of each piston body (41, 46) has a non-cylindrical surface in the region along the base end of the blade (42, 47).

  In the upper piston member (40), the center axis (41a) of the upper piston body (41) substantially coincides with the center axis (75a) of the upper eccentric portion (75) of the drive shaft (70). Further, the lower piston member (45) has the center axis (46a) of the lower piston body (46) substantially coincided with the center axis (76a) of the lower eccentric portion (76) of the drive shaft (70). To do.

  Each blade (42, 47) is a portion formed in a slightly thick rectangular flat plate shape. Each blade (42, 47) protrudes from the corresponding piston main body (41, 46) toward the radially outer side of the piston main body (41, 46). The upper blade (42) is formed integrally with the upper piston body (41), and the lower blade (47) is formed integrally with the lower piston body (46).

  The upper blade (42) of the upper piston member (40) fits into the blade accommodation hole (32) of the upper cylinder (30). The upper blade (42) partitions the upper fluid chamber (34) formed in the upper cylinder (30) into a low pressure chamber on the suction port (33) side and a high pressure chamber on the discharge port (24) side.

  The lower blade (47) of the lower piston member (45) is fitted into the blade accommodation hole (37) of the lower cylinder (35). The lower blade (47) partitions the lower fluid chamber (39) formed in the lower cylinder (35) into a low pressure chamber on the suction port (38) side and a high pressure chamber on the discharge port (29) side. .

The height H _{p1 of the} upper piston member (40) and the height H _{p2 of} the lower piston member (45) are equal to each other (see FIG. 2). In the upper piston member (40), the height of the upper piston body (41) and the height of the upper blade (42) are equal. In the lower piston member (45), the height of the lower piston body (46) is equal to the height of the lower blade (47).

  In the upper piston member (40), the upper blade body (42) is located on the radially outer side of the upper piston body (41) with respect to the two-dot chain line shown in FIG. 5, and the remaining part is the upper piston body. (41). The two-dot chain line shown in FIG. 5 is an arc whose diameter is equal to the outer diameter of the upper piston body (41) and whose center is located on the central axis (41a) of the upper piston body (41).

  Further, in the lower piston member (45), the lower blade (47) is a portion located on the outer side in the radial direction of the lower piston body (46) with respect to the two-dot chain line shown in FIG. A lower piston body (46). The two-dot chain line shown in FIG. 5 is an arc whose diameter is equal to the outer diameter of the lower piston body (46) and whose center is located on the central axis (46a) of the lower piston body (46).

<bush>
Each of the upper cylinder (30) and the lower cylinder (35) is provided with a pair of bushes (43, 48). Each bush (43, 48) is a small plate-like member having a flat front surface and an arcuate back surface.

  One upper bush (43) of the upper cylinder (30) is provided in each bush accommodating portion (32a) of the upper cylinder (30). Each upper bush (43) of the upper cylinder (30) has a back surface in sliding contact with the wall surface of the bush housing (32a). The pair of upper bushes (43) provided in the upper cylinder (30) sandwich the upper blade (42) fitted in the blade accommodation hole (32) of the upper cylinder (30) from both sides. The upper blade (42) of the upper piston member (40) is supported by the upper cylinder (30) via the upper bush (43) so as to be swingable and movable back and forth.

  One lower bush (48) of the lower cylinder (35) is provided in each bush accommodating portion (37a) of the lower cylinder (35). As for each lower bush (48) of a lower cylinder (35), each back surface is slidably contacted with the wall surface of a bush accommodating part (37a). The pair of lower bushes (48) provided on the lower cylinder (35) sandwich the lower blade (47) fitted in the blade accommodation hole (37) of the lower cylinder (35) from both sides. The lower blade (47) of the lower piston member (45) is supported by the lower cylinder (35) via the lower bush (48) so as to be swingable and movable back and forth.

-Detailed shape of piston member-
The detailed shape of each piston member (40, 45) will be described with reference to FIG.

<Piston body>
As described above, the piston main body (41, 46) of each piston member (40, 45) is a part formed in a slightly thick cylindrical shape.

An outer diameter [phi] D _po1 upper piston body (41), the outer diameter [phi] D _po2 the lower piston body (46), equal to each other (φD _po1 = φD _po2). On the other hand, the inner diameter [phi] D _pi2 the lower piston body (46) is smaller than the inner diameter [phi] D _pi1 upper piston body _{(41) (φD pi1> φD} pi2). Therefore, the lower piston body (46) of the radial thickness of the _{((φD po2 -φD pi2) /} 2) is, in the radial direction of the upper piston body (41) thickness _{((φD po1 -φD pi1) /} 2 Thicker than). The height of the upper piston body (41) is equal to the height of the lower piston body (46).

The upper piston body (41), the ratio of the inner diameter [phi] D _pi1 to the outer diameter _{φD po1 (φD pi1 / φD po1} ) is 0.7. The lower piston body (46), the ratio of the inner diameter [phi] D _pi2 to the outer diameter _{φD po2 (φD pi2 / φD po2} ) is 0.6.

The inner diameter φD _pi1 of the upper piston body (41) is slightly larger than the outer diameter φD _e1 of the upper eccentric part (75), and the inner diameter φD _pi2 of the lower piston body (46) is _smaller than that of the lower eccentric part (76). It is slightly larger than the outer diameter φD _e2 . The ratio of the inner diameter [phi] D _pi2 the lower piston body to the inner diameter [phi] D _pi1 upper piston body (41) (46) (φD pi2 / φD pi1) , the upper eccentric portion lower eccentric portion to the outer diameter [phi] D _e1 (75) ( 76) is substantially equal to the ratio (φD _e2 / φD _e1 ) of the outer diameter φD _e2 (φD _pi2 / φD _pi1 = φD _e2 / φD _e1 ).

<blade>
As described above, each blade (42, 47) is a portion formed in a slightly thick rectangular flat plate shape.

The length L _b1 of the upper blade (42) is longer than the length L _b2 of the lower blade (47). The ratio (L _b1 / L _b1 ) of the length L _b1 of the upper blade (42) to the length L _b2 of the lower blade (47) is 1.1.

The length L _b1 of the upper blade (42) has an outer diameter from a distance L ₁ from the central axis of the upper piston body (41) (41a) until the protruding end of the upper blade (42), the upper piston body (41) This is a value obtained by subtracting half of φD _po1 (L _b1 = L ₁ −φD _po1 / 2). The length L _b2 of the lower blade (47), from the distance L ₂ to the tip of the lower blade (47) from the central axis of the lower piston body (46) (46a), the lower piston body (46 ) _Is a value obtained by subtracting half of the outer diameter φD _po2 (L _b2 = L ₂ −φD _po2 / 2).

The thickness W _b1 of the upper blade (42) is equal to the thickness W _b2 of the lower blade (47) (W _b1 = W _b2 ). Further, the height H _p1 of the upper blade (42) is equal to the height H _p2 of the lower blade (47) (H _p1 = H _p2 ).

As described above, each blade (42, 47), each thickness _{W b1, W b2} are equal to each other, one each of the height _{H p1, H p2} are equal to each other, respective lengths _{L b1, L b2} Are different from each other. The material of each blade (42, 47) is the same. Therefore, the mass M _b1 of the upper blade (42) is larger than the mass M _b2 of the lower blade (47) (M _b1 > M _b2 ). The ratio of the mass _{M b1} of the upper blade (42) relative to the mass _{M b2} of the lower blade (47) _(M b1 _{/ M b2),} the length of the upper blade (42) to the length _{L b2} of the lower blade (47) It is equal to the ratio of _{L b1 (L b1 / L b1} ).

<Mass of piston member>
The upper piston body in the radial thickness (41) than _{((φD po1 -φD pi1) /} 2) is, in the radial direction of the lower piston body (46) thickness _{((φD po2 -φD pi2) /} 2) Is also thin. Therefore, the mass of the upper piston body (41) is smaller than the mass of the lower piston body (46).
On the other hand, as described above, the mass M _b1 of the upper blade (42) is larger than the mass M _b2 of the lower blade (47). The mass M ₁ of the upper piston member (40) is smaller than the mass M ₂ of the lower piston member (45) (M ₁ <M ₂ ). The ratio (M ₁ / M ₂ ) of the mass M ₁ of the upper piston member (40) to the mass M ₂ of the lower piston member (45) is 0.8.

-Driving action-
The operation of the rotary compressor (1) will be described with reference to FIGS.

  When the electric motor (10) drives the drive shaft (70), the piston members (40, 45) of the compression mechanism (15) are driven by the drive shaft (70). Each piston member (40, 45) is periodically displaced as shown in FIG. 7 every time the drive shaft (70) rotates in the corresponding cylinder (30, 35). However, the period of displacement of the upper piston member (40) and the period of displacement of the lower piston member (45) are shifted by 180 ° (that is, a half cycle).

  In each cylinder (30, 35), the volume of the high pressure chamber and the low pressure chamber of the fluid chamber (34, 39) changes with the displacement of the piston member (40, 45). In each cylinder (30, 35), a suction stroke for sucking refrigerant from the suction port (33, 38) into the fluid chamber (34, 39) and compression for compressing the refrigerant sucked into the fluid chamber (34, 39) A stroke and a discharge step of discharging the compressed refrigerant from the discharge port (24, 29) to the outside of the fluid chamber (34, 39) are performed.

  The refrigerant compressed in the upper fluid chamber (34) of the upper cylinder (30) is discharged into the space above the front head (20) through the discharge port (24) of the front head (20). The refrigerant compressed in the lower fluid chamber (39) of the lower cylinder (35) is discharged from the lower fluid chamber (39) through the discharge port (29) of the rear head (25), and is compressed by the compression mechanism (15). It flows into the space above the front head (20) through a passage (not shown) formed in the front. The refrigerant discharged from the compression mechanism (15) into the internal space of the casing (2) flows out of the casing (2) through the discharge pipe (6).

  Lubricating oil is stored at the bottom of the casing (2). This lubricating oil is supplied to the compression mechanism (15) through the oil supply passage (71) formed in the drive shaft (70), and is supplied to the sliding portion of the compression mechanism (15).

−Piston member movement and oscillation moment−
As described above, each piston member (40, 45) driven by the drive shaft (70) is periodically displaced as shown in FIG. 7 every time the drive shaft (70) rotates once. The movement of the piston member (40, 45) is revolving around the rotation center axis (70a) of the drive shaft (70) and the center axis (75a, 76a) of the corresponding eccentric part (75, 76). It can be broken down into a swinging motion. The swinging motion of the piston member (40, 45) is “the piston member (40, 45) reciprocates around the central axis (41a, 46a) of the piston body (41, 46) within a predetermined angular range. Is an exercise that rotates automatically.

  As described above, the period of movement of the upper piston member (40) and the lower piston member (45) is shifted by 180 ° (that is, a half period). As shown in FIG. 7, the upper piston member (40) and the lower piston member (45) rotate in opposite directions.

  The swinging moment generated by the swinging motion of the piston members (40, 45) becomes an excitation force that vibrates the rotary compressor (1). For this reason, if the difference between the swinging moment of the upper piston member (40) and the swinging moment of the lower piston member (45) is large, the excitation force acting on the rotary compressor (1) increases, and the rotary compressor The vibration of (1) may be excessive.

  The swinging moment of the piston member (40,45) is expressed as "the moment of inertia of the piston member (40,45) around the central axis (41a, 46a) of the piston body (41,46)" and "piston member (40,45 ) Of swing angular acceleration ”. Therefore, in order to suppress the difference between the swinging moment of the upper piston member (40) and the swinging moment of the lower piston member (45), the inertia moment around the central axis (41a) of the upper piston member (40) It is necessary to reduce the difference in the moment of inertia around the central axis (46a) of the lower piston member (45). The swing angular acceleration of the piston member (40, 45) is the angular acceleration of the rotational motion of the piston member (40, 45).

Here, the inertia moment I of the object is obtained by integrating mr ² over the entire volume of the object, assuming that the mass of the mass point located at a distance r from the rotation axis of the object is m ( I = ∫mr ² dV). When changing the inertial moment of the object by changing the mass of the object, the amount of change in the inertial moment of the object increases as the region where the mass is changed is further away from the rotation axis of the object. Therefore, when changing the moment of inertia of the piston member (40, 45), the piston body (41, 46) is closer to the piston body (41, 46) closer to the central axis (41a, 46a) of the piston body (41, 46). When the mass of the blade (42, 47) close to the central axis (41a, 46a) of 46) is changed, the amount of change in the moment of inertia of the piston member (40, 45) increases.

  Therefore, in the compression mechanism (15) of the present embodiment, the mass of the upper blade (42) of the upper piston member (40) having the upper piston body (41) having a relatively small thickness is set to be relatively small. It is larger than the mass of the lower blade (47) of the lower piston member (45) having the thick lower piston body (46). For this reason, the difference in the moment of inertia between the upper piston member (40) and the lower piston member (45) can be reduced while suppressing an increase in the mass of the upper blade (42).

Here, if the inertia moment of the upper piston member length equal virtual lower blade length of the upper blade (47) and I _1i, lower piston member relative to the moment of inertia I _1i of the virtual upper piston member ( The ratio (I ₂ / I _1i ) of the inertia moment I _{2 in} 45) is 1.1. On the other hand, the ratio (I ₂ / I ₁ ) of the inertia moment I ₂ of the lower piston member (45) to the inertia moment I ₁ of the upper piston member (40) of the present embodiment is 1.0.

Thus, in the compression mechanism (15) of the present embodiment, the inertia moment I _{1 of the} upper piston member (40) is compared to the case where the length of the upper blade (42) is equal to the length of the lower blade (47). the difference of the inertia moment I ₂ of the lower piston member (45) is reduced with. As a result, the difference between the swing moment of the upper piston member (40) and the swing moment of the lower piston member (45) is reduced, and the vibration of the rotary compressor (1) is suppressed.

-Effect of Embodiment 1-
In the present embodiment, the mass of the upper blade (42) of the upper piston member (40) having the upper piston having a relatively small thickness is set to the lower piston member (45 having the lower piston having a relatively thick thickness). ) Larger than the mass of the lower blade (47). For this reason, the difference in the moment of inertia between the upper piston member (40) and the lower piston member (45) can be reduced while keeping the amount of change in the mass of the upper blade (42) small. If the difference in inertia moment between the two piston members (40, 45) is reduced, the difference in swinging moment between the two piston members (40, 45) is reduced.

  As described above, according to the present embodiment, in the swing piston type rotary compressor (1) having two piston members (40, 45) having different shapes, the amount of change in the mass of the upper blade (42) is changed. The difference in swing moment between the two piston members (40, 45) can be reduced while keeping it small. Therefore, according to the present embodiment, the amount of change in the configuration of the upper blade (42) (in this embodiment, the length of the upper blade (42)) is suppressed, and the reliability of the rotary compressor (1) is secured. The vibration of the rotary compressor (1) can be suppressed.

  Here, when the length of the blade (42, 47) is increased, the portion of the blade (42, 47) supported by the cylinder (30, 35) via the bush (43, 48) (that is, the bush (43 , 48), the region on the tip side becomes longer than the portion slidably contacting. On the other hand, an external force does not act on the region of the blade (42, 47) on the tip side of the portion supported by the cylinder (30, 35). That is, the shape of the region of the blade (42, 47) on the tip side of the portion supported by the cylinder (30, 35) has no influence on the function of the blade (42, 47).

On the other hand, in the present embodiment, the upper blade (42) has the same thickness as the lower blade (47), and the upper blade (42) has a larger mass than the lower blade (47). The length L _b1 of the upper blade (42) is longer than the length L _b2 of the lower blade (47) (L _b1 > L _b2 ). Therefore, according to this embodiment, the mass of the upper blade (42) is made larger than the mass of the lower blade (47) without affecting the function of the upper blade (42). 40, 45) can be reduced.

-Modification of Embodiment 1-
In the rotary compressor (1) of the present embodiment, the length L _b1 of the upper blade (42) and the length L _b2 of the lower blade (47) are matched (L _b1 = L _b2 ), and the upper blade (42) _Is made thicker than the thickness W _b2 of the lower blade (47) (W _b1 > W _b2 ), so that the mass M _b1 of the upper blade (42) is changed to the mass M of the lower blade (47). _It may be larger than _b2 .

In the rotary compressor (1) of the present embodiment, the length L _b1 of the upper blade (42) is made longer than the length L _b2 of the lower blade (47) (L _b1 > L _b2 ) By making the thickness W _b1 of the blade (42) thicker than the thickness W _b2 of the lower blade (47) (W _b1 > W _b2 ), the mass M _b1 of the upper blade (42) is reduced to the lower blade (47). ) Mass M _b2 .

<< Embodiment 2 >>
Embodiment 2 will be described. The rotary compressor (1) of the present embodiment is different from the first embodiment in the shape of the lower piston member (45). Here, the difference between the rotary compressor (1) of the present embodiment and the rotary compressor (1) of the first embodiment will be described.

As shown in FIG. 8, in the compression mechanism of the present embodiment (15), and the length L _b2 of the lower blade (47) becomes equal to the length L _b1 of the upper blade (42). The thickness _{W b2} of the lower blade (47) is equal to the thickness _{W b1} of the upper blade (42), the height _{H b2} of the lower blade (47) is the height _{H b1} of the upper blade (42) The equal points are the same as in the first embodiment.

  In the compression mechanism (15) of this embodiment, a light hole (47a) is formed only in the lower blade (47) of the upper blade (42) and the lower blade (47). The light hole (47a) penetrates the lower blade (47) in the height direction. The light hole (47a) is formed at the tip of the lower blade (47). Specifically, a region closer to the tip than the portion of the lower blade (47) supported by the lower cylinder via the lower bush (48) (that is, the portion that is in sliding contact with the lower bush (48)). In addition, a light hole (47a) is formed.

The mass M _b2 of the lower blade (47) in which the light hole (47a) is formed is smaller than the mass M _b1 of the upper blade (42) in which the light hole (47a) is not formed (M _b2 <M _b1 ). . That is, also in the compression mechanism (15) of the present embodiment, as in the first embodiment, the mass of the upper blade (42) of the upper piston member (40) having the upper piston body (41) having a relatively small thickness. M _b1 is larger than the mass M _b2 of the lower blade (47) of the lower piston member (45) having the lower piston body (46) having a relatively large thickness. Therefore, according to the present embodiment, similarly to the first embodiment, it is possible to reduce the vibration moment of the two piston members (40, 45) and suppress the vibration of the rotary compressor (1).

  Further, as described above, the shape of the region on the tip side of the lower blade (47) that is supported by the lower cylinder has no influence on the function of the lower blade (47). In this embodiment, a light hole (47a) is formed in this region of the lower blade (47). Therefore, according to this embodiment, the mass of the lower blade (47) is made smaller than the mass of the upper blade (42) without affecting the function of the lower blade (47). Can reduce the difference between the swing moments of (40, 45).

-Modification of Embodiment 2-
In the compression mechanism (15) of the present embodiment, by forming a groove on the side surface of the tip of the lower blade (47), the mass _Mb2 of the lower blade (47) is changed to the upper blade on which no groove is formed. You may make it smaller than mass _Mb1 of (42).

In the compression mechanism (15) of the present embodiment, by forming one or a plurality of light holes penetrating the lower blade (47) in the thickness direction at the tip of the lower blade (47), The mass M _b2 of the lower blade (47) may be smaller than the mass M _b1 of the upper blade (42) where no light hole is formed.

  As described above, the present invention is useful for a two-cylinder rotary compressor.

1 Rotary compressor
30 Upper cylinder (first cylinder)
35 Lower cylinder (second cylinder)
40 Upper piston member (first piston member)
41 Upper piston body (first piston body)
42 Upper blade (first blade)
45 Lower piston member (second piston member)
46 Lower piston body (second piston body)
47 Lower blade (second blade)
70 Drive shaft
75 Upper eccentric part (first eccentric part)
76 Lower eccentric part (second eccentric part)

Claims (5)

A first cylinder (30) and a second cylinder (35);
A first piston member (40) housed in the first cylinder (30);
A second piston member (45) housed in the second cylinder (35);
A rotary compressor comprising a drive shaft (70) for driving the first piston member (40) and the second piston member (45),
The first piston member (40) has a cylindrical first piston main body (41) and a flat plate shape that is integral with the first piston main body (41) and extends outward from the first piston main body (41). A first blade (42),
The second piston member (45) has a cylindrical second piston main body (46) and a flat plate shape that is integral with the second piston main body (46) and extends outward from the second piston main body (46). A second blade (47),
The drive shaft (70)
A first eccentric part (75) formed in a cylindrical shape eccentric to the rotation center axis (70a) of the drive shaft (70) and into which the first piston body (41) is fitted;
A second eccentric portion (76) that is formed in a cylindrical shape that is eccentric with respect to the rotation center axis (70a) of the drive shaft (70) and into which the second piston body (46) is fitted;
In the drive shaft (70), the amount of eccentricity of the first eccentric portion (75) is equal to the amount of eccentricity of the second eccentric portion (76), and the outer diameter of the first eccentric portion (75) is the second eccentricity. Larger than the outer diameter of the part (76),
The outer diameter of the first piston body (41) is equal to the outer diameter of the second piston body (46),
The rotary compressor according to claim 1, wherein a mass of the first blade (42) is larger than a mass of the second blade (47). In claim 1,
One or both of the length and thickness of the first blade (42) is longer than that of the second blade (47). In claim 1,
The rotary compressor according to claim 1, wherein the first blade (42) is longer in length than the second blade (47) and has a thickness equal to the thickness of the second blade (47). In any one of Claims 1 thru | or 3,
The rotary compressor according to claim 1, wherein a material of the first piston member (40) is the same as a material of the second piston member (45). In any one of Claims 1 thru | or 4,
The second piston member around the central axis (46a) of the second piston body (46) with respect to the moment of inertia of the first piston member (40) around the central axis (41a) of the first piston body (41). 45) The rotary compressor characterized in that the ratio of the moment of inertia of 45) is 1 or more and smaller than the ratio of the mass of the second piston member (45) to the mass of the first piston member (40).

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