JP2014077386A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary compressor capable of enlarging an operation range in a low speed operation zone, suppressing degradation of efficiency in a high speed operation zone, and reducing costs.SOLUTION: A rotary compressor includes: a cylinder 50 formed with an intake passage 51 and a discharge hole 53; and a piston 31 having a cylindrical portion 80 and a blade portion 90 which are revolved by rotation of a shaft 22. The cylinder 50 is provided with a bypass passage 55 extended from a position of a rotation angle 90° or more with respect to a prescribed position of the blade portion 90 as a rotation starting point to a position overlapped to the intake passage in an axial view, on an inner peripheral face of the cylinder 50. The bypass passage 55 is formed to choke at a prescribed rotational frequency or more.

Description

  The present invention relates to a rotary compressor.

  Conventionally, a rotary compressor exists as a compressor provided in a refrigeration apparatus. In a rotary compressor, a compression chamber is formed between a cylinder and a part of a roller or blade disposed in the cylinder, and the volume of the compression chamber is changed as the roller rotates to compress the refrigerant. Yes. Conventionally, in such a compressor, the expansion of the operation range has been studied, and in particular, the expansion of the operation range in the low-speed operation region is desired.

  Therefore, in the rotary compressor disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-211681), a bypass hole is formed in the cylinder in addition to the suction hole and the discharge hole. The tube is connected. Further, a chuck valve is provided in the bypass pipe so that the chuck valve is opened during low-speed operation and is closed during high-speed operation.

  In the rotary compressor of Patent Document 1, the operation range in the low-speed operation region can be expanded by opening the chuck valve and flowing the intake gas to the intake pipe during low-speed operation. In addition, since the chuck valve is closed during high-speed operation, it is possible to suppress a decrease in efficiency in the high-speed operation region.

  However, in this rotary compressor, since a chuck valve is essential, the structure is complicated and the cost is increased.

  Then, the subject of this invention is providing the rotary compressor which can achieve the expansion of the operating range in a low-speed driving | operation area | region, and suppression of the efficiency fall in a high-speed driving | operation area | region, and can suppress cost.

  A rotary compressor according to a first aspect of the present invention includes a cylinder chamber forming member in which a suction passage and a discharge passage are formed, and a piston. The piston has a cylindrical portion and a blade portion. The cylindrical portion is accommodated in the cylinder chamber and revolves by the rotation of the shaft. The blade part partitions the cylinder chamber together with the outer peripheral surface of the cylindrical part. The blade portion forms a compression chamber together with the outer peripheral surface of the cylindrical portion to compress the refrigerant sucked from the suction passage and discharge it to the discharge passage. A bypass passage is formed in the cylinder chamber forming member. The bypass passage extends from a predetermined position of the blade portion on the inner peripheral surface of the cylinder chamber forming member to a position overlapping the suction passage as viewed in the axial direction from a position with a rotation angle of 90 ° or more. The bypass passage is formed so as to choke at a predetermined rotational speed or more.

  In the present invention, for example, when the bypass passage extends from the predetermined position of the blade portion to the suction passage from the predetermined position of the blade portion on the inner peripheral surface of the cylinder chamber forming member, The refrigerant being compressed in the compression chamber can be directly returned to the suction passage through the passage. Further, for example, the bypass passage communicates with the compression chamber so as to overlap with the suction passage as viewed in the axial direction from a position with a rotation angle of 90 ° or more starting from a predetermined position of the blade portion on the inner peripheral surface of the cylinder chamber forming member When extending in this way, the refrigerant being compressed in the compression chamber can be directly returned to the suction side of the compression chamber via the bypass passage. Therefore, in the present invention, the volume to be compressed in the compression chamber can be substantially reduced. Therefore, the operation range in the low speed operation region can be expanded. On the other hand, since the bypass passage chokes in the high-speed operation range, that is, when the rotation speed is equal to or higher than the predetermined rotation speed, it is possible to suppress a decrease in volume efficiency.

  As described above, in the present invention, since a conventional valve is not required, expansion of the operation range in the low-speed operation region and suppression of efficiency reduction in the high-speed operation region can be achieved while suppressing cost. .

  The piston may have a configuration in which the cylindrical portion and the blade portion are integrated, or may have a configuration in which the cylindrical portion and the blade portion are separate.

  A rotary compressor according to a second aspect of the present invention is the rotary compressor according to the first aspect of the present invention, wherein the bypass passage has an end on the opposite side to the suction side and an inner peripheral surface of the cylinder chamber forming member. In FIG. 3, the blade portion is formed so as to be located between a position at a rotation angle of 90 ° from a predetermined position of the blade portion and a discharge start angle at which the discharge of the refrigerant into the discharge passage is started.

  In the present invention, the refrigerant to be discharged to the discharge passage can be prevented from returning to the suction side through the bypass passage.

  A rotary compressor according to a third aspect of the present invention is the rotary compressor according to the first aspect or the second aspect of the present invention, wherein the bypass passage is compressed at the suction side end with the suction passage in the axial direction. It is formed so as to be located at the boundary with the chamber.

  In the present invention, the refrigerant flowing through the bypass passage and the refrigerant flowing through the suction passage flow in substantially the same place in the compression chamber. As described above, according to the present invention, it is not necessary to bother the end of the bypass passage on the suction side to communicate with the suction passage, so that it is possible to reduce processing effort and cost.

  A rotary compressor according to a fourth aspect of the present invention is the rotary compressor according to any one of the first aspect to the third aspect of the present invention, and the cylinder chamber forming member includes a cylinder. The cylinder is a member in which a cylinder chamber is formed inside the inner peripheral surface thereof. The bypass passage is a groove formed in one end surface or both end surfaces in the axial direction of the cylinder.

  In the present invention, it is possible to achieve expansion of the operating range in the low-speed operating region and suppression of efficiency reduction in the high-speed operating region by simple processing such as forming grooves in the cylinder.

  A rotary compressor according to a fifth aspect of the present invention is the rotary compressor according to any one of the first to third aspects of the present invention, and the cylinder chamber forming member includes a cylinder. The cylinder is a member in which a cylinder chamber is formed inside the inner peripheral surface thereof. The bypass passage is a hole formed in the cylinder.

  In the present invention, it is possible to achieve the expansion of the operating range in the low-speed operating region and the suppression of the efficiency reduction in the high-speed operating region by simple processing such as forming a hole in the cylinder.

  The rotary compressor which concerns on the 6th viewpoint of this invention is a rotary compressor which concerns on either of the 1st viewpoint of this invention-the 5th viewpoint, Comprising: A bypass channel and the narrow part which chokes more than predetermined rotation speed, And a wide part wider than the narrow part.

  In the present invention, the bypass passage is choked at a predetermined rotational speed or more with a simple structure in which a narrow portion having a narrower width than other portions is formed in a part of the bypass passage.

  A rotary compressor according to a seventh aspect of the present invention is the rotary compressor according to the fourth aspect of the present invention, wherein the bypass passage has a shallow groove portion that chokes at a predetermined rotational speed or more and a depth smaller than the shallow groove portion. And a deep deep groove portion.

  In the present invention, the bypass passage is choked at a predetermined rotational speed or more with a simple structure in which a shallow groove portion having a shallower depth than other portions is formed in a part of the bypass passage.

  The rotary compressor which concerns on the 8th viewpoint of this invention is a rotary compressor which concerns on the 1st viewpoint or 2nd viewpoint of this invention, Comprising: A cylinder formation member is a cylinder, a front head, and a rear head. The front head and the rear head cover the cylinder from the axial direction.

  In the present invention, even if the bypass passage is formed in any of the cylinder, the front head, and the rear head, the choke is choked at a predetermined rotational speed or more.

  In the rotary compressor according to the present invention, it is possible to achieve the expansion of the operation range in the low speed operation region and the suppression of the decrease in efficiency in the high speed operation region, and the cost can be suppressed.

The schematic longitudinal cross-sectional view of a rotary compressor. The figure which looked at the cylinder and the piston from the upper part. In order to show a bypass passage, it is the figure which looked at the cylinder and the piston from the upper part. The graph which shows the relationship between the rotation speed of the cylindrical part of a piston, and the bypass amount per unit time. The graph which shows the relationship between the rotation speed of the cylindrical part of a piston, and the bypass amount per rotation of a cylindrical part. The figure which looked at the cylinder and piston which concern on the modification A from upper direction. The figure which looked at the cylinder and the piston from the top in order to show the formation method of the bypass passage concerning modification A. The figure which looked at the cylinder and piston which concern on the modification B from upper direction. The figure which looked at the cylinder and piston which concern on the modification C from upper direction. The figure which looked at the cylinder and piston which concern on the modification D from upper direction.

  Hereinafter, an embodiment of a rotary compressor according to the present invention will be described with reference to the drawings.

(1) Overall Configuration of Rotary Compressor FIG. 1 is a schematic longitudinal sectional view of a rotary compressor 10. In the following description, a direction along a center axis O (hereinafter simply referred to as “center axis O” as appropriate) of the motor 21 to be described later is referred to as an axial direction or a vertical direction.

  As shown in FIG. 1, the rotary compressor 10 is a one-cylinder rotary compressor, and includes a casing 11, a drive mechanism 20 and a compression mechanism 30 disposed in the casing 11. In the rotary compressor 10, the compression mechanism 30 is disposed below the drive mechanism 20 in the casing 11.

  The rotary compressor 10 is a device used for compressing a refrigerant in a refrigeration apparatus such as an air conditioner or a heat pump type hot water heater, and sucks the refrigerant from an accumulator 95 of the refrigeration apparatus and compresses the refrigerant to a high temperature and a high pressure. The discharged refrigerant is discharged from the discharge pipe 25 toward the gas cooler of the refrigeration apparatus.

(2) Detailed Configuration (2-1) Drive Mechanism As shown in FIG. 1, the drive mechanism 20 is housed in the upper part of the internal space of the casing 11 and drives the compression mechanism 30. The drive mechanism 20 includes a motor 21 that is a drive source and a shaft 22 that is a drive shaft attached to the motor 21.

  The motor 21 is a motor for rotationally driving the shaft 22, and mainly includes a rotor 23 and a stator 24. The rotor 23 has a shaft 22 inserted in its internal space, and rotates together with the shaft 22. The rotor 23 is composed of laminated electromagnetic steel plates and a magnet embedded in the rotor body. The stator 24 is disposed outside the rotor 23 in the radial direction via a predetermined space. The stator 24 includes laminated electromagnetic steel plates and a coil wound around the stator body. The motor 21 rotates the rotor 23 together with the shaft 22 by electromagnetic force generated in the stator 24 by passing an electric current through the coil.

  The shaft 22 is inserted into the rotor 23 and rotates about the central axis O. In addition, the crank pin 22 a that is an eccentric portion of the shaft 22 is inserted into a cylindrical portion 80 (described later) of the piston 31 of the compression mechanism 30, and the cylindrical portion 80 is capable of transmitting the rotational force from the rotor 23. It fits in. The shaft 22 rotates according to the rotation of the rotor 23, rotates the crank pin 22 a eccentrically, and revolves the cylindrical portion 80 of the piston 31 of the compression mechanism 30. That is, the shaft 22 has a function of transmitting the driving force of the motor 21 to the compression mechanism 30. Note that an oil flow path is formed in the shaft 22 for guiding the oil accumulated in the lower part of the internal space of the casing 11 to the sliding portion.

(2-2) Compression Mechanism FIG. 2 is a view of the cylinder 50 and the piston 31 as viewed from above. FIG. 3 is a view of the cylinder 50 and the piston 31 as viewed from above in order to show the bypass passage 55.

  As shown in FIG. 1, the compression mechanism 30 is accommodated on the lower side in the casing 11. The compression mechanism 30 compresses the refrigerant sucked from the accumulator 95 through the suction pipe 96. The compression mechanism 30 is a rotary type compression mechanism, and mainly includes a front head 40, a cylinder 50, a piston 31, and a rear head 60. Further, the refrigerant compressed in the compression chamber S1 of the compression mechanism 30 is discharged from a discharge hole (not shown) through the muffler space S2 to a space where the motor 21 is disposed and the lower end of the discharge pipe 25 is located. Here, the compression chamber S1 is a space in which the refrigerant sucked from the suction passage 51 (described later) of the cylinder 50 is compressed and discharged to the discharge notch 53 (described later).

(2-2-1) Cylinder The cylinder 50 is a metal casting member. As shown in FIG. 2, the cylinder 50 is formed with a suction passage 51 that sucks low-pressure refrigerant in the refrigeration cycle and flows it to the cylinder chamber 52. The cylinder chamber 52 is a cylindrical space formed inside the inner peripheral surface 50 a 1 of the cylinder 50, and is a space into which the refrigerant sucked from the suction passage 51 flows. Here, the lower end of the cylinder chamber 52 is closed by a rear head 60 described later, and the upper end is closed by a front head 40 described later. Therefore, the front head 40, the cylinder 50, and the rear head 60 are “cylinder chamber forming members” that form the cylinder chamber 52. The “inner peripheral surface” of the “cylinder chamber forming member” coincides with the inner peripheral surface 50 a 1 of the cylinder 50. The suction passage 51 extends from the inner peripheral surface 50a1 of the cylinder 50 toward the outer peripheral surface 50b1, the first end that is one end is opened in the inner peripheral surface 50a1 of the cylinder 50, and the second end that is the other end is the cylinder. 50 is opened on the outer peripheral surface 50b1. A distal end portion of a suction pipe 96 extending from the accumulator 95 is inserted into the second end of the suction passage 51. Further, the cylinder chamber 52 accommodates a piston 31 for compressing the refrigerant flowing into the cylinder chamber 52. The cylinder chamber 52 is partitioned by a piston 31 to form a compression chamber S1. Further, a discharge notch 53 is formed in the cylinder 50 by cutting a part of the discharge side end surface of the inner peripheral surface 50a1 of the cylinder 50 toward the outside.

  Further, the cylinder 50 is formed with a blade swing space 54 in which a bush 35 and a blade portion 90 of the piston 31 described later are disposed. The blade portion 90 of the piston 31 is supported by the cylinder 50 via the bush 35 so as to be swingable. The blade swinging space 54 is formed so as to extend from the cylinder chamber 52 toward the outer peripheral side in the vicinity of the suction passage 51 in a plan view. The bush 35 is a substantially semi-cylindrical member, and is accommodated in the blade swing space 54 so as to sandwich the blade portion 90 of the piston 31.

  Further, as shown in FIG. 3, a bypass passage 55 is formed on the upper end surface which is one end surface in the axial direction of the cylinder 50. The bypass passage 55 is configured by a groove recessed downward from the upper end surface, and guides the refrigerant being compressed in the compression chamber S1 to the suction side. The bypass passage 55 is open at both ends on the inner peripheral surface 50a1 of the cylinder 50 and communicates with the compression chamber S1. Specifically, the suction side end 55a, which is the end on the suction side of the bypass passage 55, is located in the vicinity of the suction passage 51, and specifically, located at a position overlapping the suction passage 51 in the axial direction. ing. More specifically, the suction side end 55a of the bypass passage 55 is located on the inner peripheral surface 50a1 of the cylinder 50 at the boundary between the suction passage 51 and the compression chamber S1 when viewed in the axial direction. Further, if the rotation angle of the crank pin 22a of the shaft 22 when the top dead center position of the blade portion 90 of the piston 31 is set as the starting point is θ (see FIG. 2), the side opposite to the suction side of the bypass passage 55 is assumed. The suction side opposite end 55b, which is the end, is located at a predetermined rotation angle θb (see FIG. 3) on the inner peripheral surface 50a1 of the cylinder 50. Here, the predetermined rotation angle θb is preferably set to be less than the discharge start angle. The discharge start angle is an angle at which the refrigerant starts to be discharged into the discharge passage, and varies depending on the pressure condition of the refrigeration system. For example, when the discharge start angle is 200 °, the predetermined rotation angle θb may be about 180 ° as shown in FIG. The discharge passage is a passage for discharging the refrigerant compressed in the compression chamber S1 to the muffler space S2, and is formed by a discharge notch 53 of the cylinder 50 and a discharge hole of the front head 40 described later.

  In this way, the bypass passage 55 returns the refrigerant being compressed in the compression chamber S1 from the suction side opposite end 55b to the suction side of the compression chamber S1 via the suction side end 55a.

  The bypass passage 55 has a predetermined rotational speed α (for example, 40 rps, see FIG. 4) due to the cross-sectional area in the flow direction of the passage extending from the suction-side opposite end 55b to the suction-side end 55a. ) Choke when above. That is, the bypass passage 55 is formed so that its axial cross-sectional area has a minimum cross-sectional area that chokes when the rotational speed of the cylindrical portion 80 is equal to or greater than the predetermined rotational speed α.

  Here, FIG. 4 is a graph showing the relationship between the rotational speed of the cylindrical portion 80 of the piston 31 and the amount of bypass per unit time. The bypass amount is the amount of refrigerant flowing from the middle of the compression chamber S1 to the suction side via the bypass passage 55. FIG. 5 is a graph showing the relationship between the rotational speed of the cylindrical portion 80 of the piston 31 and the bypass amount per rotation of the cylindrical portion 80.

  In the present embodiment, the bypass passage 55 is formed so as to choke when the rotational speed of the cylindrical portion 80 becomes equal to or higher than the predetermined rotational speed α, so that the rotational speed of the cylindrical portion 80 becomes equal to or higher than the predetermined rotational speed α. Then, as shown in FIG. 4, the amount of bypass per unit time is constant. Therefore, as shown in FIG. 5, when the amount of bypass per one rotation of the cylindrical portion 80 is equal to or greater than the predetermined rotational speed α, the state is considerably small. On the other hand, when the rotational speed of the cylindrical portion 80 of the piston 31 is less than the predetermined rotational speed α, the bypass amount per unit time can be increased according to the rotational speed. Thus, in this embodiment, when the rotation speed of the cylindrical portion 80 is less than the predetermined rotation speed α, the refrigerant in the compression chamber S1 is returned to the suction side via the bypass passage 55 to return to the compression chamber S1. The volume to be substantially compressed can be reduced. On the other hand, when the rotational speed of the cylindrical portion 80 is equal to or higher than the predetermined rotational speed α, a decrease in volumetric efficiency due to a large amount of refrigerant being returned to the suction side through the bypass passage 55 can be suppressed.

  In the present embodiment, the bypass passage 55 is formed so that the cross-sectional area in the axial direction is the same at any position.

(2-2-2) Piston The piston 31 is accommodated in the cylinder chamber 52. The piston 31 has a cylindrical portion 80 and a blade portion 90, and these are integrated members. The cylindrical portion 80 is attached to and integrated with a crank pin 22 a that is an eccentric portion of the shaft 22. Therefore, the cylindrical portion 80 revolves around the shaft 22 by the rotation of the shaft 22. As described above, the blade portion 90 forms the compression chamber S1 by partitioning the cylinder chamber 52 together with the outer peripheral surface 80a of the cylindrical portion 80. Further, the blade portion 90 is accommodated in the blade swing space 54 formed in the cylinder 50 and is supported by the cylinder 50 via the bush 35 so as to be swingable as described above. The blade portion 90 is slidable with the bush 35.

(2-2-3) Front Head As shown in FIG. 1, the front head 40 includes a front head disc portion 41 that closes the upper surface of the cylinder 50, and a peripheral edge of the front head opening at the center of the front head disc portion 41. And a front head boss portion 42 extending upward. The front head boss portion 42 has a cylindrical shape and functions as a bearing for the shaft 22.

  The front head 40 has a discharge hole. From the discharge hole, the refrigerant compressed in the compression chamber S1 whose volume changes in the cylinder chamber 52 of the cylinder 50 is intermittently discharged. The front head 40 is provided with a discharge valve that opens and closes the outlet of the discharge hole. The discharge valve opens due to a pressure difference when the pressure in the compression chamber S1 becomes higher than the pressure in the muffler space S2, and discharges the refrigerant from the discharge hole to the muffler space S2.

(2-2-4) Rear Head The rear head 60 includes a rear head disc portion 61 that closes the lower surface of the cylinder 50, and a rear head boss portion 62 that serves as a bearing extending downward from the peripheral edge of the central opening of the rear head disc portion 61. Have The front head disk portion 41, the rear head disk portion 61, and the cylinder 50 form a cylinder chamber 52 as shown in FIG.

(2-2-5) Muffler The muffler 70 is attached to the upper surface of the front head 40 as shown in FIG. The muffler 70 forms a muffler space S2 together with the upper surface of the front head disc portion 41 and the outer peripheral surface of the front head boss portion 42 to reduce noise accompanying refrigerant discharge. As described above, the muffler space S2 and the compression chamber S1 communicate with each other through the discharge hole when the discharge valve is open.

  Further, the muffler 70 is formed with a central muffler opening through which the front head boss portion 42 penetrates, and a muffler discharge hole through which a refrigerant flows from the muffler space S2 to the accommodation space of the motor 21 above.

  The muffler space S2, the accommodation space for the motor 21, the space above the motor 21 where the discharge pipe 25 is located, the space where the lubricating oil is accumulated below the compression mechanism 30, etc. are all connected, and the high pressure is equal. A space is formed.

(3) Operation and Flow of Refrigerant In the rotary compressor 10, the refrigerant is compressed by changing the volume of the compression chamber S1 by the movement of the piston 31 of the compression mechanism 30 that revolves due to the eccentric rotation of the crank pin 22a. Then, the refrigerant compressed in the compression chamber S1 is guided from the compression chamber S1 to the muffler space S2 through the discharge holes. The refrigerant introduced into the muffler space S2 is discharged from the muffler discharge hole of the muffler 70 to a space above the muffler space S2. The refrigerant discharged to the outside of the muffler space S2 passes through the space between the rotor 23 and the stator 24 of the motor 21, cools the motor 21, and then is discharged from the discharge pipe 25 to the high-pressure refrigerant pipe of the refrigeration apparatus. Is done.

(4) Features (4-1)
Conventionally, in a rotary compressor, expansion of the operation range has been studied, and in particular, expansion of the operation range in a low-speed operation region is desired. Therefore, in the rotary compressor disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-211681), a bypass hole is formed in the cylinder in addition to the suction hole and the discharge hole. The tube is connected. Further, a chuck valve is provided in the bypass pipe so that the chuck valve is opened during low-speed operation and is closed during high-speed operation.

  In the rotary compressor of Patent Document 1, the operation range in the low-speed operation region can be expanded by opening the chuck valve and flowing the intake gas to the intake pipe during low-speed operation. In addition, since the chuck valve is closed during high-speed operation, it is possible to suppress a decrease in efficiency in the high-speed operation region. However, in this rotary compressor, since a chuck valve is essential, the structure is complicated and the cost is increased.

  Therefore, in the present embodiment, a bypass passage 55 is formed in the cylinder 50. The bypass passage 55 is a groove formed on the upper end surface of the cylinder 50, and starts from a predetermined position (specifically, a top dead center position) of the blade portion 90 of the piston 31 on the inner peripheral surface 50 a 1 of the cylinder 50. The inner circumferential surface 50a1 of the cylinder 50 extends from a position at a predetermined rotation angle θb (specifically, approximately 180 °) to a boundary position between the suction passage 51 and the compression chamber S1 when viewed in the axial direction. Further, the bypass passage 55 is formed so that the rotational speed of the cylindrical portion 80 of the piston 31 is choked at a predetermined rotational speed α or more by the sectional area in the axial direction.

  As described above, in the present embodiment, the refrigerant in the compression chamber S1 can be led to the suction side via the bypass passage 55 in the low speed operation region even if a conventional valve is not provided. The volume to be compressed can be reduced. Therefore, the operation range in the low speed operation region can be expanded. Further, since the bypass passage 55 chokes in the high-speed operation region, it is possible to suppress a decrease in volumetric efficiency. That is, in the present embodiment, it is possible to achieve the expansion of the operation range in the low speed operation region and the suppression of the efficiency decrease in the high speed operation region while suppressing the cost.

  Further, in the present embodiment, the bypass passage 55 is formed such that the suction side end 55a thereof is located on the inner peripheral surface 50a1 of the cylinder 50 at the boundary between the suction passage 51 and the compression chamber S1 when viewed in the axial direction. Thus, the refrigerant flowing through the suction passage 51 and the refrigerant flowing through the bypass passage 55 flow to substantially the same position in the compression chamber S1. Thereby, it is possible to easily return to the suction side in the compression chamber S1.

(4-2)
In the present embodiment, the bypass passage 55 has a suction end opposite end 55b on the inner peripheral surface 50a1 of the cylinder 50 at a predetermined position (specifically, top dead center position) of the blade portion 90 of the piston 31 at the start of suction. ) As a starting point, it is located at a position of a predetermined rotation angle θb (in the present embodiment, approximately 180 °). Here, the predetermined rotation angle θb is an angle smaller than the discharge start angle. Therefore, in this embodiment, it can be avoided that the refrigerant to be discharged is returned to the suction side via the bypass passage 55.

(5) Modification (5-1) Modification A
FIG. 6 is a view of the cylinder 150 and the piston 31 according to Modification A as viewed from above. FIG. 7 is a view of the cylinder 150 and the piston 31 as viewed from above in order to show a method of forming the bypass passage 155 according to the modification A.

  In the above embodiment, the bypass passage 55 has been described as being formed by a groove formed in the upper end surface of the cylinder 50, but is not limited thereto. Specifically, for example, a cylinder 150 as shown in FIG. 6 may be employed. In this modification, the bypass passage 155 formed in the cylinder 150 is only different from the bypass passage 55 of the above-described embodiment, and therefore, the other components are denoted by the same reference numerals and description thereof is omitted.

  The bypass passage 155 formed in the central portion 150a of the cylinder 150 is configured by a hole. This hole is not formed in the end surface of the center part 150a of the cylinder 150 like the said embodiment, but is formed in the thick part.

  Hereinafter, a method for forming the bypass passage 155 will be described.

  First, as shown in FIG. 7, from the position of the predetermined rotation angle θb starting from a predetermined position (top dead center position) of the blade portion 90 of the piston 31 at the start of suction on the inner peripheral surface 150a1 of the cylinder 150, A base hole 185 a extending toward the center and penetrating to the outer peripheral surface of the cylinder 150 is formed. Further, a base hole 185 b extending from the suction passage 51 in the rotation direction and penetrating to the outer peripheral surface of the cylinder 150 is formed. Further, a base hole 185c penetrating from a position on the outer peripheral surface of the cylinder 150 toward a different position is formed so as to intersect the base hole 185a and the base hole 185b. Here, the base holes 185a, 185b, and 185c are formed by drilling. Then, as shown in FIG. 6, one opening is located at a predetermined rotation angle θb starting from a predetermined position (top dead center position) of the blade portion 90 of the piston 31 at the start of suction on the inner peripheral surface 150 a 1 of the cylinder 150. In order to form a single bypass passage 155 such that the other opening is positioned so as to overlap the suction passage 51 in the axial direction, the base holes 185a, 185b, 185c are wasted. Processing to close the hole portion is performed (see the hatched black portion in FIG. 6). Thus, the suction side end 155a, which is the suction side end of the bypass passage 155, is located at a position overlapping the suction passage 51 in the axial direction, and the suction side opposite side end which is the opposite side of the suction side 155b opens to a position of a predetermined rotation angle θb starting from a predetermined position (top dead center position) of the blade portion 90 of the piston 31 at the start of suction on the inner peripheral surface 150a1 of the cylinder 150 as in the above embodiment. Become. In this modification, the suction side end 155a of the bypass passage 155 is open to a side portion of the suction passage 51, and the bypass passage 155 and the suction passage 51 are communicated with each other. That is, the bypass passage 155 is a passage through which the refrigerant being compressed in the compression chamber S1 can be directly returned to the suction passage 51.

  As described above, in this modification, by forming the bypass passage 155 formed of a hole in the central portion 150a of the cylinder 150, the same operational effects as in the above embodiment can be obtained easily.

(5-2) Modification B
FIG. 8 is a view of the cylinder 250 and the piston 31 according to Modification B as viewed from above.

  In the above embodiment, it has been described that the bypass passage 55 is configured only by the groove, but is not limited thereto.

  Specifically, instead of the cylinder 50 of the above embodiment, for example, a cylinder 250 in which a bypass passage 255 as shown in FIG. 8 is formed may be employed. The bypass passage 255 formed in the central portion 250 a of the cylinder 250 is configured by a groove 265 formed in the upper end surface and a hole 266 extending in the axial direction from the groove to the suction passage 51. In this modification, the bypass passage 255 formed in the cylinder 250 is only different from the bypass passage 55 of the above embodiment, and therefore, the other components are denoted by the same reference numerals and description thereof is omitted.

  The groove 265 of the bypass passage 255 according to this modification is located at a position where the suction side end 265a, which is the end on the suction side, overlaps the suction passage 51 in the axial direction. In this modification, the suction side opposite end 265b, which is the end opposite to the suction side of the groove 265 of the bypass passage 255, opens at the same position as the above embodiment on the inner peripheral surface 250a1 of the cylinder 250. ing. The hole 266 of the bypass passage 255 is formed by drilling or the like so as to penetrate the suction passage 51 from the upper end surface of the central portion 250a of the cylinder 250. The suction side end 265a of the groove 265 and the hole 266 communicate with each other. In this modification, the suction side end of the bypass passage 255 is constituted by the lower end portion (not shown) of the hole 266, and the suction side opposite end is constituted by the suction side opposite end 265b of the groove 265. become.

  As described above, in this modification, the hole 266 communicating with the groove 265 is also communicated with the suction passage 51, so that the refrigerant in the compression chamber S1 flowing through the groove 265 can be easily compressed in the hole 266. It is possible to return to the suction passage 51 via the. Therefore, it is possible to obtain the same effect as the above embodiment.

(5-3) Modification C
In the embodiment described above, the bypass passage 55 is formed so that the cross-sectional area in the axial direction is the same at any position. However, the present invention is not limited to this.

  Specifically, instead of the cylinder 50 of the above embodiment, for example, a cylinder 350 in which a bypass passage 355 as shown in FIG. 9 is formed may be employed. The bypass passage 355 formed in the central portion 350a of the cylinder 350 according to the present modification is configured to have a narrow portion 365 and a wide portion 366 that is wider than the narrow portion 365. Specifically, the bypass passage 355 has a bypass direction in which the direction in which the refrigerant flows from the suction side opposite end 355b which is the end opposite to the suction side of the bypass passage 355 to the suction side end 355a which is the suction side end. A narrow portion 365 is formed on the upstream side in the bypass direction, and a wide portion 366 is formed on the downstream side of the narrow portion 365 in the bypass direction. Here, the “width” direction refers to a direction that is orthogonal to the direction in which the refrigerant flows in the bypass passage 355 and that is not the axial direction. The narrow portion 365 of the bypass passage 355 is formed such that the cross-sectional area in the bypass direction is a cross-sectional area that chokes when the rotational speed of the cylindrical portion 80 of the piston 31 is greater than or equal to the predetermined rotational speed α. FIG. 9 is a view of the cylinder 350 and the piston 31 according to Modification C as viewed from above. Even when this configuration is adopted, the suction-side end 355a and the suction-side opposite end 355b of the bypass passage 355 are opened at the same positions as in the above embodiment on the inner peripheral surface 350a1 of the cylinder 350.

  Even in this case, when the rotational speed of the cylindrical portion 80 becomes equal to or higher than the predetermined rotational speed α, choking is performed in the narrow portion 365, so that a decrease in volumetric efficiency in the high-speed operation region can be suppressed. On the other hand, in the low-speed operation region, similarly to the above embodiment, the refrigerant being compressed in the compression chamber S1 can be returned from the suction side opposite end 355b to the suction side to the compression chamber S1 via the suction side end 355a. Therefore, the volume to compress can be made small.

(5-4) Modification D
As a configuration of the bypass passage, in addition to the configuration described in the modification example C, a configuration in consideration of the depth may be used. Specifically, instead of the cylinder 50 of the above embodiment, for example, a cylinder 450 in which a bypass passage 455 as shown in FIG. 10 is formed may be employed. The bypass passage 455 formed in the central portion 450 a of the cylinder 450 is configured to have a shallow groove portion 465 and a deep groove portion 466. The shallow groove portion 465 is formed so as to choke when the rotational speed of the cylindrical portion 80 of the piston 31 is equal to or higher than a predetermined rotational speed α. The deep groove portion 466 is formed to be deeper than the shallow groove portion 465. FIG. 10 is a view of the cylinder 450 and the piston 31 according to Modification C as viewed from above. Also at this time, the suction-side end 455a and the suction-side opposite end 455b of the bypass passage 455 are opened at the same positions as in the above embodiment on the inner peripheral surface 450a1 of the cylinder 450.

  Even in this case, when the rotational speed of the cylindrical portion 80 is equal to or higher than the predetermined rotational speed α, choking is performed in the shallow groove portion 465, so that a decrease in volumetric efficiency in the high speed operation region can be suppressed. On the other hand, in the low speed operation region, similarly to the above-described embodiment, the refrigerant being compressed in the compression chamber S1 can be returned from the suction side opposite end 455b to the suction side to the compression chamber S1 via the suction side end 455a. Therefore, the volume to compress can be made small.

  As described above, in the bypass passages 355 and 455 of the present modification, the cross-sectional area in the axial direction is changed. In this modification, a simple structure in which a part of the bypass passages 355 and 455 has a narrow width or a shallow depth, and the cylinder portion 80 chokes when the rotational speed of the cylindrical portion 80 exceeds a predetermined rotational speed α. ing. In this modification, the cross-sectional area in the axial direction of the narrow portion 365 and the shallow groove portion 465 is the cross-sectional area that the bypass passages 355 and 455 choke when the rotational speed of the cylindrical portion 80 is equal to or higher than the predetermined rotational speed α. However, the choke flow rate of the bypass passages 355 and 455 may be adjusted by adjusting the passage lengths of the narrow portion 365 and the shallow groove portion 465.

(5-5) Modification E
In the above embodiment, the bypass passage 55 has been described as being formed on the upper end surface of the cylinder 50, but the present invention is not limited to this. For example, the bypass passage 55 may be formed on the lower end surface that is one end surface of the cylinder 50 in the axial direction. Further, for example, the bypass passage 55 may be formed on the upper end surface and the lower end surface which are both end surfaces in the axial direction of the cylinder 50.

  Even in these cases, the same effects as those of the above-described embodiment can be achieved.

(5-6) Modification F
In the above-described embodiment, it has been described that the predetermined rotation angle θb may be less than the discharge start angle. Specifically, it may be between approximately 90 ° and the discharge start angle. That is, the suction side opposite end 55b of the bypass passage 55 is located between a position at a rotation angle of 90 ° and a discharge start angle starting from a predetermined position (top dead center position) of the blade portion 90 of the piston 31. It is sufficient if it is formed.

  Even in this case, the refrigerant being compressed in the compression chamber S1 can be returned to the suction side via the bypass passage 55 in the low speed operation region, so that the volume compressed in the compression chamber S1 can be reduced. On the other hand, in the high-speed operation region, as in the above embodiment, choking is performed, so that a decrease in volumetric efficiency can be suppressed.

(5-7) Modification G
In the above embodiment, the single-cylinder rotary compressor 10 with one cylinder has been described, but the present invention can also be applied to a two-cylinder rotary compressor with two cylinders.

(5-8) Modification H
In the above embodiment, the rotary compressor 10 including the piston 31 in which the cylindrical portion 80 and the blade portion 90 are integrally formed has been described as an example. However, the present invention is not limited to this, and a roller that rotates and The present invention can also be applied to a rotary compressor including a piston having a blade that is a separate body.

(5-9) Modification I
In the above embodiment, it has been described that the bypass passage 55 is formed in the cylinder 50. However, the present invention is not limited to this. For example, a bypass passage having the same shape as that of the above embodiment may be formed in the front head 40 and the rear head 60. Even in this case, it is possible to obtain the same effect as the above embodiment.

  In the case where a bypass passage is formed in the front head 40 and the rear head 60 and the refrigerant that is being compressed is directly returned to the suction passage 51 of the cylinder 50, the suction passage 51 is provided from the upper end surface or the lower end surface of the cylinder 50. It is necessary to form a hole penetrating to the top.

    The present invention can be variously applied to a rotary compressor including a cylinder and a piston having a cylindrical portion and a blade portion.

10 Rotary compressor 22 Shaft 31 Piston 40 Front head (Cylinder chamber forming member)
50, 150, 250, 350, 450 Cylinder (Cylinder chamber forming member)
60 Rear head (cylinder chamber forming member)
50a1, 150a1, 250a1, 350a1, 450a1 Cylinder inner peripheral surface 51 Suction passage 52 Cylinder chamber 53 Discharge notch (discharge passage)
55, 155, 255, 355, 455 Bypass passage 55a, 155a, 255a, 265a, 355a, 455a Inlet side end (inlet side end of bypass passage)
55b, 155b, 255b, 355b, 455b Suction side opposite end (end opposite to suction side of bypass passage)
80 cylindrical portion 80a outer peripheral surface of cylindrical portion 90 blade portion 365 narrow portion 366 wide portion 465 shallow groove portion 466 deep groove portion S1 compression chamber

JP 2004-211681 A

Claims (8)

A cylinder chamber forming member (40, 50, 60, 150, 250, 350, 450) in which a suction passage (51) and a discharge passage (53) are formed;
A cylinder portion (80) housed in the cylinder chamber (52) and revolved by the rotation of the shaft (22) and an outer peripheral surface (80a) of the cylinder portion partition the cylinder chamber and compress the refrigerant sucked from the suction passage. A piston (31) having a blade portion (90) that forms a compression chamber (S1) that discharges into the discharge passage.
With
The cylinder chamber forming member has an inner circumferential surface (50a1, 150a1, 250a1, 350a1, and 450a1) that has the suction passage and the suction passage as viewed in the axial direction from a position with a rotation angle of 90 ° or more starting from a predetermined position of the blade portion. A bypass passage (55, 155, 255, 355, 455) extending to the overlapping position is formed,
The bypass passage is formed to choke at a predetermined rotational speed or higher,
Rotary compressor (1). The bypass passage has an end opposite to the suction side (55b, 155b, 255b, 355b, 455b) at a rotation angle of 90 ° starting from a predetermined position of the blade portion on the inner peripheral surface of the cylinder chamber forming member. It is formed so as to be located between the position from the position to the discharge start angle at which the refrigerant starts to be discharged to the discharge passage,
The rotary compressor according to claim 1. The bypass passage (55, 355, 455) is formed such that the suction side end (55a, 355a, 455a) is located at the boundary between the suction passage and the compression chamber in the axial direction. Yes,
The rotary compressor according to claim 1 or 2. The cylinder chamber forming member includes a cylinder in which the cylinder chamber is formed inside the inner peripheral surface thereof,
The bypass passage is a groove formed in one end surface or both end surfaces in the axial direction of the cylinder.
The rotary compressor of any one of Claims 1-3. The cylinder chamber forming member includes a cylinder in which the cylinder chamber is formed inside the inner peripheral surface thereof,
The bypass passage (155) is a hole formed in the cylinder.
The rotary compressor of any one of Claims 1-3. The bypass passage (355) includes a narrow portion (365) that chokes at a predetermined rotational speed or more, and a wide portion (366) that is wider than the narrow portion.
The rotary compressor of any one of Claims 1-5. The bypass passage (455) includes a shallow groove portion (465) that chokes at a predetermined rotational speed or more, and a deep groove portion (466) that is deeper than the shallow groove portion.
The rotary compressor according to claim 4. The cylinder forming member is a cylinder, and a front head (40) and a rear head (60) that cover the cylinder from the axial direction.
The rotary compressor according to claim 1 and 2.

Images