Patent Publication Number: US-11661939-B2

Title: Rotary compressor having reciprocator and support

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Japanese Patent Application No. 2021-044527, filed on Mar. 18, 2021. The entire disclosures of Japanese Patent Application No. 2021-044527 is incorporated by reference herein. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a rotary compressor having a reciprocator and a support, and an air conditioner using such a rotary compressor. 
     Background Information 
     A rotary compressor disclosed in Japanese Patent No. 5413493 has a compression mechanism. The compression mechanism includes a piston that revolves, a vane (which may be referred to as a blade) that is integrally formed with the piston and reciprocates, and a bush that supports the vane. The bush is provided with a groove for retaining lubricating oil. 
     SUMMARY 
     A rotary compressor according to one aspect includes a casing and a compression mechanism. The casing includes an oil reservoir that stores lubricating oil therein. The compression mechanism includes a reciprocator and a support. The reciprocator defines a compression chamber. The reciprocator reciprocates along a first direction. The support has a support surface. The support surface supports the reciprocator. The support surface is provided with a first groove and a second groove. The first groove extends along a second direction intersecting the first direction. The first groove transfers the lubricating oil to the second groove. The second groove extends from a center of the first groove toward the compression chamber along the first direction. 
     In this configuration, the first groove conveys the lubricating oil to a center of the support in the second direction. Next, the second groove spreads the lubricating oil conveyed to the center in the first direction of the support. Therefore, the center of the support acquires a large amount of lubricating oil, and thus seizure at the center of the support is suppressed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a circuit diagram of an air conditioner  400 A according to a first embodiment; 
         FIG.  2    is a sectional view taken along a vertical plane of a rotary compressor  90 A; 
         FIG.  3    is a sectional view taken along a horizontal plane of a compression mechanism  40 ; 
         FIG.  4    is a perspective view of a pair of bushes  49 A; 
         FIG.  5    is a side view of one bush  49 A; 
         FIG.  6    is a side view of one bush  49 A; 
         FIG.  7    is a side view of a bush  49 B of a compressor according to a first modification of the first embodiment; 
         FIG.  8    is a side view of a hush  49 C of a compressor according to a second modification of the first embodiment; 
         FIG.  9    is a side view of a hush  49 D of a compressor according to a third modification of the first embodiment; 
         FIG.  10    is a side view of a bush  49 E of a compressor according to a fourth modification of the first embodiment; 
         FIG.  11    is a side view of a bush  49 F of a compressor according to a fifth modification of the first embodiment; and 
         FIG.  12    is a sectional view of the compression mechanism  40  of a rotary compressor  90 G according to a second embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENT(S) 
     First Embodiment 
     (1) Overall Configuration 
       FIG.  1    shows an air conditioner  400 A according to a first embodiment. The air conditioner  400 A includes an outdoor unit  100 , an indoor unit  200 , and a connection piping  300 . 
     The outdoor unit  100  includes a rotary compressor  90 A, a four-way switching valve  110 , an outdoor heat exchanger  120 , an outdoor fan  130 , an outdoor expansion valve  140 , a liquid shutoff valve  150 , and a gas shutoff valve  160 . 
     The indoor unit  200  includes an indoor heat exchanger  220  and an indoor fan  230 . 
     The connection piping  300  includes a liquid connection pipe  310  and a gas connection pipe  320 . 
     When the air conditioner  400 A performs a cooling operation, the four-way switching valve  110  forms a connection indicated by a solid line in  FIG.  1   , and a refrigerant circulates in a direction of arrow C. In the cooling operation, the indoor heat exchanger  220  functions as an evaporator and provides cold air to a user in cooperation with the indoor fan  230 . When the air conditioner  400 A performs a heating operation, the four-way switching valve  110  forms a connection indicated by a broken line in  FIG.  1   , and the refrigerant circulates in a direction of arrow H. In the heating operation, the indoor heat exchanger  220  functions as a condenser and provides warm air to the user in cooperation with the indoor fan  230 . 
     (2) Detailed Configuration of Rotary Compressor  90 A 
       FIG.  2    shows the rotary compressor  90 A. The rotary compressor  90 A sucks a low-pressure gas refrigerant and compresses the sucked low-pressure gas refrigerant to generate a high-pressure gas refrigerant. The rotary compressor  90 A includes a casing  10 , a suction pipe  15 , a discharge pipe  16 , a motor  20 , a crank shaft  30 , a compression mechanism  40 , a first oil supply mechanism  71 , and a second oil supply mechanism  72 . 
     (2-1) Casing  10 , Suction Pipe  15 , and Discharge Pipe  16   
     The casing  10  accommodates various constituent elements of the rotary compressor  90 A, the refrigerant, and the lubricating oil. The casing  10  includes a body  11 , a lid  12 , and a bottom  13  that are airtightly connected. 
     The suction pipe  15  for sucking the low-pressure gas refrigerant is attached to the body  11 . The discharge pipe  16  for discharging the high-pressure gas refrigerant is attached to the body  11 . 
     Inside the casing  10 , there is an oil reservoir  17  that stores the lubricating oil. The oil reservoir  17  is located near the bottom  13 . 
     (2-2) Motor  20   
     The motor  20  receives electric power supply from outside of the rotary compressor  90 A and generates power for driving the compression mechanism  40 . The motor  20  is attached to the body  11 . The motor  20  includes a stator  21  and a rotor  22 . 
     The stator  21  has a cylindrical shape and is fixed to the body  11 . The stator  21  converts electric power into an AC magnetic field. 
     The rotor  22  is disposed inside the stator  21 . The rotor  22  rotates by interacting with the AC magnetic field generated by the stator  21 . 
     (2-3) Crank Shaft  30   
     The crank shaft  30  is fixed to the rotor  22  to rotate about a rotation axis RA with the rotor  22 . The crank shaft  30  transmits a rotary force generated by the rotor  22  to the compression mechanism  40 . 
     The crank shaft  30  includes a main shaft  31  concentric with the rotation axis RA and an eccentric portion  32  eccentric with the rotation axis RA. A part of the main shaft  31  is fixed to the rotor  22 . The eccentric portion  32  is located in the compression mechanism  40 . 
     (2-4) Compression Mechanism  40   
     The compression mechanism  40  compresses a low-pressure gas refrigerant to generate a high-pressure gas refrigerant. The compression mechanism  40  includes a cylinder  41 , a piston  42 , a vane  43 , a front head  46 , a rear head  47 , a muffler  48 , and a pair of bushes  49 A. 
       FIG.  3    is a sectional view of the compression mechanism  40 . The cylinder  41  is a rigid component. The cylinder  41  is provided with a first cavity  41   a , a second cavity  41   b , and a suction port  41   c . The first cavity  41   a  and the second cavity  41   b  are connected to each other. The suction port  41   c  is for taking in a high-pressure gas refrigerant, and is connected to the suction pipe  15 . 
     The piston  42  is a cylindrical member. The eccentric portion  32  is attached to a cavity of the piston  42 . The rotation of the crank shaft  30  causes the piston  42  to revolve while being in contact with the cylinder  41 . 
     The vane  43  is a plate-shaped member. The vane  43  is formed integrally with the piston  42 . 
     Each of the pair of bushes  49 A is a semicircular columnar member. The pair of bushes  49 A are disposed on different sides of the vane  43  in order to support the vane  43 . 
     The piston  42  is accommodated in the first cavity  41   a  of the cylinder  41 . The vane  43  and the pair of bushes  49 A are accommodated in the second cavity  41   b  of the cylinder  41 . 
     A part of the second cavity  41   b  accommodating the vane  43  is a vane rear space  41   d . The vane  43  has a first end  43   a  and a second end  43   b . The first end  43   a  faces the first cavity  41   a . The second end  43   b  is opposite the first end  43   a  and faces the vane rear space  41   d.    
     The vane  43  reciprocates substantially in a first direction M 1 . That is, when the piston  42  moves away from the second cavity  41   b , the vane  43  protrudes from the second cavity  41   b . Meanwhile, when the piston  42  approaches the second cavity  41   b , the vane  43  retreats to the second cavity  41   b.    
     The vane  43  defines the compression chamber  45  in cooperation with the cylinder  41  and the piston  42 . The compression chamber  45  is a space surrounded by the cylinder  41 , the piston  42 , and the vane  43  in contact with each other. The compression chamber  45  includes a first compression chamber  45   a  and a second compression chamber  45   b . The first compression chamber  45   a  increases in volume as the crank shaft  30  rotates. The first compression chamber  45   a  is used to suck the low-pressure gas refrigerant. The second compression chamber  45   b  decreases in volume as the crank shaft  30  rotates. The second compression chamber  45   b  is used to increase a pressure of the refrigerant. 
     In  FIG.  2    again, the front head  46  closes an upper surface of the cylinder  41 . The front head  46  is provided with a discharge port  46   a  for discharging the high-pressure gas refrigerant from the compression chamber  45 . The front head  46  has a large diameter. The front head  46  is fixed to the body  11  of the casing  10 . As a result, the compression mechanism  40  as a whole is fixed to the casing  10 . The rear head  47  closes a lower surface of the cylinder  41 . The muffler  48  is attached to the front head  46  so as to cover the discharge port  46   a . The muffler  48  reduces noise caused by pulsation of the pressure of the high-pressure gas refrigerant discharged from the discharge port  46   a.    
     (2-5) First Oil Supply Mechanism  71  and Second Oil Supply Mechanism  72   
     The first oil supply mechanism  71  and the second oil supply mechanism  72  supply the lubricating oil in the oil reservoir  17  to the compression mechanism  40 . At least one of the first oil supply mechanism  71  or the second oil supply mechanism  72  supplies part of the lubricating oil to the vane rear space  41   d . The lubricating oil in the vane rear space  41   d  is used for lubricating the vane  43  and the bushes  49 A. 
     (3) Detailed Configuration of Bushes  49 A 
       FIG.  4    is a perspective view of the pair of bushes  49 A. Each of the bushes  49 A has a support surface S that supports the vane  43 . The support surface S is parallel to both the first direction M 1  and a second direction M 2 . The second direction M 2  intersects with the first direction M 1 . 
     As shown in  FIG.  5   , the support surface S is provided with a first groove  51  and a second groove  52 . The first groove  51  extends along the second direction M 2 . The first groove  51  has a first end  51   a , a second end  51   b , and a center  51   c . Both the first end  51   a  and the second end  51   b  reach a contour CT of the support surface S. 
     The first groove  51  conveys the lubricating oil acquired at the first end  51   a  and the second end  51   b  toward the center  51   c . Further, the first groove  51  transfers the acquired lubricating oil to the second groove  52 . 
     The second groove  52  has a third end  52   a  and a fourth end  52   b . The third end  52   a  is closer to the compression chamber  45  than the fourth end  52   b . The fourth end  52   b  is farther from the compression chamber  45  than the third end  52   a . The second groove  52  passes through the center  51   c  of the first groove  51 . The second groove  52  extends from the center  51   c  toward the first cavity  41   a , that is, toward the compression chamber  45  along the first direction M 1 . The third end  52   a  is separated from the contour CT of the support surface S. The fourth end  52   b  reaches the contour CT of the support surface S. The second groove  52  acquires lubricating oil from the fourth end  52   b . The second groove  52  also acquires lubricating oil from the first groove  51  in the center  51   c . The lubricating oil acquired by the second groove  52  is at least partially conveyed to the third end  52   a.    
     (4) Dimensions 
     As is described with reference to  FIG.  6   , an amount of lubricating oil contributing to lubrication of the bushes  49 A can be secured by setting dimensions of each part as follows, for example. 
     A width W 51  of the first groove  51  is 1/20 or more of a length L 1  of a side E 1  of the support surface S extending in the first direction M 1 , or a width W 52  of the second groove  52  is 1/40 or more of a length L 2  of a side E 2  of the support surface S extending in the second direction M 2 . 
     The first groove  51  and the second groove  52  have an area GA on the support surface S, the area GA being 1/50 or more of an area SA of the support surface S. 
     (5) Characteristics 
     (5-1) 
     The first groove  51  conveys the lubricating oil to a center of the hush  49 A in the second direction M 2 . Next, the second groove  52  spreads the lubricating oil conveyed to the center in the first direction M 1  of the hush  49 A. Therefore, the center of the hush  49 A acquires a large amount of lubricating oil, and thus seizure in the center of the bush  49 A is suppressed. 
     (5-2) 
     Both the first end  51   a  and the second end  51   b  of the first groove  51  reach the contour CT of the support surface S. Therefore, the first groove  51  can acquire the lubricating oil at both ends of the bush  49 A, that is, on a side of the first cavity  41   a , and on a side of the vane rear space  41   d.    
     (5-3) 
     The third end  52   a  of the second groove  52  is separated from the contour CT of the support surface S. Therefore, the lubricating oil acquired in the center of the bush  49 A is prevented from being discharged toward the compression chamber  45  through the second groove  52 . 
     (5-4) 
     A ratio of the width W 51  of the first groove  51  to the side E 1  of the support surface S is 1/20 or more, or a ratio of the width W 52  of the second groove  52  to the side E 2  of the support surface S is 1/40 or more. Therefore, a predetermined ratio of dimension is involved in lubrication, and thus a degree of lubrication of the bush  49 A further increases. 
     (5-5) 
     A ratio of the area GA constituted by the first groove  51  and the second groove  52  to the area SA of the support surface S is 1/50 or more. Therefore, a predetermined ratio of area is involved in lubrication, and thus the degree of lubrication of the bush  49 A further increases. 
     (5-6) 
     The vane  43  is formed integrally with the piston  42 . Lubrication of the vane  43  moving simultaneously with the piston  42  is thus ensured. 
     (5-7) 
     Since seizure inside the rotary compressor  90 A is suppressed, a product life of the air conditioner  400 A is improved. 
     (6) Modifications 
     (6-1) First Modification of First Embodiment 
     In the bush  49 A according to the first embodiment, the fourth end  52   b  of the second groove  52  reaches the contour CT of the support surface S. Alternatively, as can be seen in a bush  49 B shown in  FIG.  7   , the fourth end  52   b  may be separated from the contour CT of the support surface S. For example, the fourth end  52   b  of the second groove  52  is disposed in the center  51   c  of the first groove  51 . 
     In this configuration, the second groove  52  also has a function of retaining the lubricating oil at a center of the bush  49 B, and thus seizure at the center of the hush  49 B is suppressed. 
     (6-2) Second Modification of First Embodiment 
     In the bush  49 A according to the first embodiment, the fourth end  52   b  of the second groove  52  reaches the contour CT of the support surface S. Alternatively, as can be seen in a bush  49 C shown in  FIG.  8   , the fourth end  52   b  may be separated from the contour CT of the support surface S. For example, the fourth end  52   b  of the second groove  52  is disposed between the contour CT on the side of the vane rear space  41   d  and the center  51   c  of the first groove  51 . 
     In this configuration, the second groove  52  also has a function of retaining the lubricating oil in a center of the bush  49 C, and thus seizure at the center of the bush  49 C is suppressed. 
     (6-3) Third Modification of First Embodiment 
     In the bush  49 A according to the first embodiment, the support surface S is provided with one second groove  52 . Alternatively as can be seen in a bush  49 D shown in  FIG.  9   , the support surface S may be provided with a plurality of second grooves  52 . 
     In this configuration, the plurality of second grooves  52  are disposed in the center of the bush  49 D. Therefore, the center receives supply of the lubricating oil from each of the plurality of second grooves  52 , and thus more amount of lubricating oil is supplied to the center. 
     (6-4) Fourth Modification of First Embodiment 
     In the bush  49 A according to the first embodiment, the support surface S is provided with the first groove  51  and the second groove  52 . Alternatively, as can be seen in a bush  49 E shown in  FIG.  10   , the support surface S may be further provided with a branch groove  53  extending from the third end  52   a  of the second groove  52  in the second direction M 2 . 
     In this configuration, the branch groove  53  is provided in a center of the bush  49 E. Therefore, the branch groove  53  further increases the degree of lubrication in the center. 
     (6-5) Fifth Modification of First Embodiment 
     In the hush  49 A according to the first embodiment, the support surface S is provided with the first groove  51  and the second groove  52 . Alternatively, as can be seen in a bush  49 F shown in  FIG.  11   , a first branch groove  531  and a second branch groove  532  may extend from the third end  52   a  of the second groove  52  on the support surface S. Here, the first branch groove  531  extends in a direction intersecting the first direction M 1 . The second branch groove  532  extends in a direction intersecting the first direction M 1  and being different from the direction in which the first branch groove  531  extends. The first direction M 1  and the first branch groove  531  form an acute angle α. The first direction M 1  and the second branch groove  532  form an acute angle β. 
     In this configuration, the first direction M 1  in which the second groove  52  extends forms the acute angles α and β with the first branch groove  531  or the second branch groove  532 . Therefore, the first branch groove  531  and the second branch groove  532  spread the lubricating oil in both the first direction M 1  and the second direction M 2 , and thus the degree of lubrication of the bush  49 F further increases. 
     Second Embodiment 
     (1) Configuration 
       FIG.  12    shows the compression mechanism  40  of a rotary compressor  90 G mounted in an air conditioner according to a second embodiment. The air conditioner according to the second embodiment has the same configuration as the air conditioner  400 A according to the first embodiment except that the rotary compressor  900  is mounted instead of the rotary compressor  90 A. 
     The compression mechanism  40  of the rotary compressor  90 G is different from the compression mechanism  40  according to the first embodiment in that the vane  43  is formed separately from the piston  42 . A part of the second cavity  41   b  accommodating the vane  43  is a vane rear space  41   d . A spring  44  is installed in the vane rear space  41   d . The spring  44  brings the vane  43  into contact with the piston  42  by pushing the vane  43  toward the first cavity  41   a.    
     In the rotary compressor  90 A according to the first embodiment, the bush  49 A has the support surface S, the first groove  51 , and the second groove  52 . On the other hand, in the rotary compressor  90 G according to the second embodiment, the support surface S, the first groove  51 , and the second groove  52  are formed on an inner wall of the second cavity  41   b  of the cylinder  41 . 
     (2) Characteristics 
     The vane  43  is formed separately from the piston  42 . Lubrication of the vane  43  moving independently from the piston  42  is thus ensured. 
     (3) Modifications 
     Any one of the modifications of the first embodiment may be applied to the second embodiment. 
     Conclusion 
     The embodiments of the present disclosure have been described above. Various modifications to modes and details should be available without departing from the object and the scope of the present disclosure recited in the claims.