Rolling piston type compressor

Abstract

A compression mechanism includes a middle side plate. The middle side plate has a first member (161) and a second member. A discharge port (164) that communicates with a first compression chamber and can discharge refrigerant compressed in the first compression chamber is formed on a first end surface (F1) on the second member side of the first member (161). A groove part (177) into which the refrigerant sucked in from a suction path flows is formed on at least one of the first end surface (F1) of the first member (161) and the second end surface on the first member (161) side of the second member. When the pressure of the refrigerant flowing into the groove part (177) is lower than the pressure of the refrigerant discharged from the discharge port (164), the maximum stress applied to the second end surface of the second member by the pressure of the refrigerant is reduced.

Description

Rolling piston type compressor

[0001] The present disclosure relates to a rolling piston compressor.

[0002] Japanese Patent Laid-Open Publication No. 2018-178793 (Patent Document 1) is a prior art document that discloses a hermetic compressor. The hermetic compressor described in Patent Document 1 includes a first cylinder, a first partition plate, a second partition plate, and a second cylinder, arranged in this order along a rotation shaft. The first cylinder has a first cylinder chamber. A partition plate space is formed between the first partition plate and the second partition plate. The second cylinder has a second cylinder chamber. Working fluid compressed in the first cylinder chamber and the second cylinder chamber is discharged into the partition plate space.

[0003] Japanese Patent Application Laid-Open No. 2018-178793

[0004] Generally, a compressor compresses a refrigerant in a compression chamber where components slide against each other, and to ensure the sliding properties of the components, gaps are provided at the sliding points, taking into consideration deformation of the components. In the hermetic compressor described in Patent Document 1, when compressed refrigerant is discharged into the partition space, stress is applied to the first partition plate and the second partition plate, which may cause deformation of the first partition plate and the second partition plate. In this case, a large gap must be provided between the components to take into consideration deformation of the components, which may result in leakage of compressed refrigerant through the gap and reduced compressor efficiency.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a highly efficient rolling piston compressor.

[0006] A rolling piston compressor according to the present disclosure includes a case and a compression mechanism. The case has a suction path and a discharge path. The compression mechanism is housed in the case and is capable of compressing refrigerant drawn through the suction path and discharging the refrigerant to the discharge path. The compression mechanism includes a rotating shaft, a first piston, a first vane, a first cylinder, a front side plate, a second piston, the second vane, the second cylinder, a rear side plate, and a middle side plate. The rotating shaft has an axis extending in a first direction. The first piston is rotatable eccentrically with respect to the axis as the rotating shaft rotates. The first vane abuts against the first piston in a direction intersecting the first direction. The first cylinder houses the first piston and the first vane, and a first compression chamber for compressing refrigerant is formed between the first piston and the first vane. The front side plate abuts against the first cylinder in the first direction and is in contact with the first compression chamber. The second piston is spaced apart from the first piston and is positioned on the opposite side of the first piston from the side where the front side plate is positioned in the first direction, and is rotatable eccentrically with respect to the axis as the rotary shaft rotates. The second vane abuts the second piston in a direction intersecting the first direction. The second cylinder houses the second piston and the second vane, and a second compression chamber that compresses refrigerant is formed between the second piston and the second vane. The rear side plate abuts the second cylinder from the opposite side of the first direction from the side where the front side plate is positioned, and is in contact with the second compression chamber. The middle side plate is positioned between the first cylinder and the second cylinder in the first direction and separates the first compression chamber from the second compression chamber. The middle side plate has a first member and a second member. The first member extends in a direction intersecting the first direction and abuts the first cylinder in the first direction. The second member extends in a direction intersecting the first direction and abuts against the second cylinder and the first member in the first direction. A discharge port is formed in a first end face of the first member facing the second member, the discharge port communicating with the first compression chamber and capable of discharging refrigerant compressed in the first compression chamber. A groove is formed in at least one of the first end face of the first member and the second end face of the second member facing the first member, into which refrigerant drawn from the suction path flows.The pressure of the refrigerant flowing into the groove is lower than the pressure of the refrigerant discharged from the discharge port, thereby reducing the maximum stress exerted on the second end surface of the second member by the pressure of the refrigerant.

[0007] In one embodiment of the present disclosure, the maximum thickness of the first member in the first direction is greater than the maximum thickness of the second member. The groove is formed in the first member.

[0008] In one embodiment of the present disclosure, the groove portion is formed in an arc shape so as to overlap with the second compression chamber when viewed from the first direction.

[0009] According to the present disclosure, a highly efficient rolling piston compressor can be provided.

[0010] 1 is a top view showing the configuration of a rolling piston compressor according to an embodiment of the present disclosure. It is a front view of the configuration of the rolling piston compressor of FIG. 1, as seen from the direction of the arrows II. It is a partial cross-sectional view of the configuration of the rolling piston compressor of FIG. 1, as seen from the direction of the arrows III-III. It is a cross-sectional view of the configuration of the rolling piston compressor of FIG. 3, as seen from the direction of the arrows IV-IV. It is an exploded perspective view showing a path through which a refrigerant is compressed in the rolling piston compressor according to an embodiment of the present disclosure. It is a cross-sectional view of the configuration of the rolling piston compressor of FIG. 1, as seen from the direction of the arrows VI-VI. It is a perspective view showing the configuration of a first member of a middle side plate according to an embodiment of the present disclosure. It is a side view showing the configuration of a first member of a middle side plate provided in a rolling piston compressor according to a comparative example. It is a cross-sectional view showing the results of a simulation analysis of deformation of a second member of a middle side plate according to a comparative example when refrigerant pressure is applied to the second member from the first member side. It is a side view of the first member of the middle side plate of FIG. 7, as seen from the direction of the arrows X. It is a cross-sectional view showing a state in which pressure of compressed refrigerant is applied to the second member of the middle side plate from the first member side.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description of the embodiments, the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0012] In the drawings, the direction perpendicular to the direction in which the axis of the rotation shaft extends and the vertical direction is designated as the X direction, the vertical direction is designated as the Y direction, and the direction in which the axis of the rotation shaft extends is designated as the Z direction. Also, in the drawings, some parts, such as the connection structure between components, are omitted. Furthermore, in Figures 4, 9, and 11, some cross-sectional parts are not hatched for the sake of convenience.

[0013] First, the overall configuration of a rolling piston compressor will be described. Fig. 1 is a top view showing the configuration of a rolling piston compressor according to an embodiment of the present disclosure. Fig. 2 is a front view of the configuration of the rolling piston compressor of Fig. 1 as seen from the direction of the arrows along line II. Fig. 3 is a partial cross-sectional view of the configuration of the rolling piston compressor of Fig. 1 as seen from the direction of the arrows along line III-III.

[0014] As shown in FIGS. 1 to 3, the rolling piston compressor 1 can be mounted on, for example, an automobile. The rolling piston compressor 1 is used, for example, for air conditioning of the automobile. The rolling piston compressor 1 in this embodiment is used to compress, for example, carbon dioxide (CO ２ ) is used as a refrigerant.

[0015] The rolling piston compressor 1 in this embodiment includes a case 10 , a compression mechanism 20 , a motor 30 , and an oil separator 40 .

[0016] The case 10 forms the outer shape of the rolling piston compressor 1. The case 10 is made of a material such as aluminum or an aluminum alloy.

[0017] The case 10 includes a first case 11 and a second case 12. The first case 11 and the second case 12 are aligned in a first direction (Z direction).

[0018] The first case 11 is provided with an intake port 13 through which a refrigerant (not shown) is drawn in. The intake port 13 penetrates an inner circumferential surface 15. The second case 12 is provided with an outlet port 14 through which the refrigerant is discharged. The outlet port 14 is located in a thick portion at an end of the case 10 in the first direction (Z direction).

[0019] The case 10 is provided with a suction path 2 and a discharge path 3. Refrigerant is drawn into the case 10 through the suction path 2. The suction port 13 constitutes a part of the suction path 2. The refrigerant is discharged to the outside of the case 10 through the discharge path 3. The discharge port 14 constitutes a part of the discharge path 3.

[0020] The compression mechanism 20 is housed in the case 10. In the present embodiment, the compression mechanism 20 is mainly disposed inside the second case 12. The compression mechanism 20 is capable of compressing the refrigerant drawn in through the suction path 2 and discharging the compressed refrigerant through the discharge path 3. The members constituting the compression mechanism 20 are made of a material such as an aluminum alloy or an iron alloy, for example.

[0021] The compression mechanism 20 includes a rotary shaft 21, a piston, a vane, a cylinder, and a plate member 25. The piston is rotatable eccentrically with respect to an axis C as the rotary shaft 21 rotates. The vane abuts against the piston in a direction perpendicular to the first direction. The cylinder houses the piston and the vane, and a compression chamber for compressing the refrigerant is formed between the piston and the vane. The plate member 25 abuts against the cylinder in the first direction and is in contact with the compression chamber.

[0022] The piston in this embodiment includes a first piston and a second piston spaced apart from each other in the first direction. The vane in this embodiment includes a first vane and a second vane. The cylinder in this embodiment includes a first cylinder and a second cylinder. The compression chamber includes a first compression chamber and a second compression chamber.

[0023] The motor 30 is housed in the case 10. In this embodiment, the motor 30 is housed in a first case 11.

[0024] The motor 30 is, for example, an electric motor. The motor 30 includes a stator 31 and a rotor 32. The stator 31 is formed by stacking a plurality of electromagnetic steel plates (not shown) in the Z direction. The stator 31 is fixed to the inner circumferential surface 15 of the first case 11. The rotor 32 is formed by stacking a plurality of electromagnetic steel plates (not shown) in the Z direction. The rotor 32 is arranged on the inner circumferential side of the stator 31 with a gap therebetween.

[0025] The oil separator 40 is provided on the discharge path 3. The oil separator 40 is provided on the discharge path 3 adjacent to the discharge port 14. The refrigerant contains lubricating oil (not shown) to maintain the sliding properties of the compression mechanism 20. The oil separator 40 separates the lubricating oil mixed in the refrigerant from the refrigerant.

[0026] Next, a detailed description will be given of the compression mechanism 20. Fig. 4 is a cross-sectional view of the configuration of the rolling piston compressor shown in Fig. 3, as viewed from the direction of the arrows along line IV-IV.

[0027] 3 and 4 , the compression mechanism 20 includes a rotary shaft 21, a first compression section 22, a second compression section 23, and a plate member 25. In the present embodiment, the plate member 25 has a front side plate 140, a middle side plate 160, and a rear side plate 190.

[0028] The rotating shaft 21 has an axis C that extends in a first direction (Z direction). In this embodiment, the rotating shaft 21 has an axis C that extends in the horizontal first direction (Z direction). Because the first direction (Z direction) is horizontal, the rolling piston compressor 1 in this embodiment is a horizontally placed compressor whose horizontal width is greater than its vertical height. Note that the axis C of the rotating shaft 21 is not limited to a configuration that extends horizontally.

[0029] The rotating shaft 21 has a fixed portion 110 , a first shaft portion 111 , a second shaft portion 112 , a third shaft portion 113 , a first eccentric shaft portion 114 , and a second eccentric shaft portion 115 .

[0030] The fixed portion 110 is fixed to the inner peripheral surface 33 of the rotor 32. As a result, when the motor 30 is driven, the rotation of the rotor 32 causes the rotation shaft 21 to rotate about the axis C.

[0031] The first shaft 111 is inserted through the front side plate 140. The second shaft 112 is inserted through the rear side plate 190. The third shaft 113 is inserted through the middle side plate 160.

[0032] Each of the first eccentric shaft portion 114 and the second eccentric shaft portion 115 is eccentric in a direction perpendicular to the first direction (Z direction) with respect to the axis C of the rotating shaft 21. The first eccentric shaft portion 114 is inserted through the first compression portion 22. The second eccentric shaft portion 115 is inserted through the second compression portion 23.

[0033] As shown in FIG. 4 , the first compression section 22 includes a first piston 120 , a first vane 122 , and a first cylinder 125 .

[0034] The first piston 120 is rotatable in an eccentric state with respect to the axis C in accordance with the rotation of the rotary shaft 21. The first piston 120 is fitted to the first eccentric shaft portion 114 in a state in which it can rotate circumferentially in the first direction (Z direction).

[0035] The first vane 122 abuts against the first piston 120 in a direction (Y direction) intersecting the first direction. A tip end 123 of the first vane 122 abuts against the outer circumferential surface 121 of the first piston 120 in the direction (Y direction) intersecting the first direction. The first vane 122 is movable in the Y direction while abutting against the first piston 120 in accordance with the rotation of the first piston 120.

[0036] The first cylinder 125 accommodates the first piston 120 and the first vane 122. The first piston 120, which rotates eccentrically, slides on an inner circumferential surface 126 of the first cylinder 125. A vane groove 127 is provided so as to be continuous with the inner circumferential surface 126. The vane groove 127 extends in the Y direction. The first vane 122 is accommodated in the vane groove 127. The side surface 124 of the first vane 122 is provided so as to slide in the vane groove 127.

[0037] A through-hole 128 is provided in the outer peripheral surface of the first cylinder 125. The through-hole 128 penetrates to the first vane 122 in the vertical direction (Y direction) perpendicular to the first direction. An elastic member 129 is inserted into the through-hole 128. The elastic member 129 biases the first vane 122 toward the first piston 120. A plate-shaped member 130 and a fastening member 131 are provided on the outer peripheral surface of the first cylinder 125. The plate-shaped member 130 is disposed with a gap from the through-hole 128. The plate-shaped member 130 supports the elastic member 129. The fastening member 131 fixes the plate-shaped member 130 to the first cylinder 125.

[0038] The first cylinder 125 defines a first compression chamber 26 between the first piston 120 and the first vane 122 for compressing the refrigerant.

[0039] Refrigerant is introduced into the first compression chamber 26 through a first suction port 143 (described later). As the first piston 120 rotates in an eccentric state, the space in the first compression chamber 26 gradually narrows, compressing the refrigerant. The compressed refrigerant is discharged from a first discharge port 164 (described later).

[0040] As shown in FIG. 3 , the second compression section 23 includes a second piston 150 , a second vane 151 , and a second cylinder 152 .

[0041] The second piston 150 is disposed at an interval from the first piston 120 on the opposite side of the first piston 120 from the side on which the front side plate 140 is disposed in the first direction (Z direction). The second piston 150 is rotatable in an eccentric state with respect to the axis C in conjunction with the rotation of the rotary shaft 21. The second piston 150 is fitted to the second eccentric shaft portion 115 in a state in which it is rotatable about its own axis in the circumferential direction in the first direction (Z direction).

[0042] The second vane 151 abuts against the second piston 150 in a direction (Y direction) intersecting the first direction. The second cylinder 152 accommodates the second piston 150 and the second vane 151.

[0043] In the second compression section 23, a second compression chamber 27 for compressing the refrigerant is formed between the second vane 151, the second cylinder 152 and the second piston 150.

[0044] Refrigerant is introduced into the second compression chamber 27 through a second intake port 180 (described later). As the second piston 150 rotates eccentrically, the space in the second compression chamber 27 gradually narrows, compressing the refrigerant. The compressed refrigerant is discharged through a second discharge port 192 (described later).

[0045] The front side plate 140 abuts against the first cylinder 125 in the first direction (Z direction). In this embodiment, the front side plate 140 abuts against the first cylinder 125 from the side where the motor 30 is disposed. The front side plate 140 abuts against the first compression chamber 26 in the first direction (Z direction).

[0046] The front side plate 140 has an outer periphery 141 and a first bearing 142. The outer periphery 141 is a portion that is sandwiched between the first case 11 and the second case 12 in the first direction (Z direction). The front side plate 140 is connected to the first case 11 and the second case 12 at the outer periphery 141 by bolts or the like. The first bearing 142 is formed by a through hole that penetrates the front side plate 140 in the first direction (Z direction). The first bearing 142 supports the first shaft 111. The first shaft 111 slides relative to the first bearing 142 as the rotating shaft 21 rotates.

[0047] An oil reservoir 28 is disposed in the front side plate 140. The oil reservoir 28 is capable of storing lubricating oil.

[0048] The middle side plate 160 is disposed between the first cylinder 125 and the second cylinder 152 in the first direction (Z direction). The middle side plate 160 separates the first compression chamber 26 and the second compression chamber 27.

[0049] The middle side plate 160 has a first member 161 and a second member 178 .

[0050] The first member 161 has a disk shape extending in a direction intersecting the first direction. The first member 161 abuts against the first cylinder 125 in the first direction (Z direction). The third shaft portion 113 of the rotating shaft 21 is inserted into an inner circumferential surface 162 of the first member 161. The third shaft portion 113 slides relative to the inner circumferential surface 162 as the rotating shaft 21 rotates.

[0051] The second member 178 has a disk shape extending in a direction intersecting the first direction. The second member 178 abuts against the second cylinder 152 and the first member 161 in the first direction (Z direction). The third shaft portion 113 of the rotating shaft 21 is inserted into an inner circumferential surface 179 of the second member 178. The third shaft portion 113 slides relative to the inner circumferential surface 179 as the rotating shaft 21 rotates.

[0052] The rear side plate 190 abuts against the second cylinder 152 from the side opposite to the side on which the front side plate 140 is disposed in the first direction (Z direction). The rear side plate 190 abuts against the second compression chamber 27 in the first direction (Z direction). The rear side plate 190 is disposed opposite the front side plate 140 in the first direction (Z direction), with the first compression chamber 26 and the second compression chamber 27 sandwiched therebetween.

[0053] The rear side plate 190 has a second bearing portion 191. The second bearing portion 191 is formed by a through-hole that penetrates the rear side plate 190 in the first direction (Z direction). The second bearing portion 191 supports the second shaft portion 112. The second shaft portion 112 slides relative to the second bearing portion 191 as the rotary shaft 21 rotates.

[0054] Next, a description will be given of a refrigerant path in the rolling piston compressor 1. Fig. 5 is an exploded perspective view showing a path through which a refrigerant is compressed in a rolling piston compressor according to an embodiment of the present disclosure. Note that, for convenience, Fig. 5 shows only components necessary for explanation, and omits other components (for example, through holes for supplying lubricating oil).

[0055] As shown in FIG. 5 , the suction path 2 and the discharge path 3 through which the refrigerant passes are provided to pass through the front side plate 140, the first cylinder 125, the middle side plate 160, the second cylinder 152, and the rear side plate 190.

[0056] A first intake port 143 is provided in the front side plate 140. The first intake port 143 penetrates the front side plate 140 in a first direction (Z direction). The first intake port 143 has an elongated hole shape in a direction perpendicular to the first direction (Z direction).

[0057] The first cylinder 125 is provided with a communication hole 132. The communication hole 132 passes through the first cylinder 125 in the first direction (Z direction).

[0058] A communication hole 170 is provided in the first member 161 of the middle side plate 160. The communication hole 170 penetrates the first member 161 in the first direction (Z direction).

[0059] A first groove 163 is provided in a first end face F1 of the first member 161 on the side of the second member 178. The first groove 163 is recessed in the first direction (Z direction).

[0060] An outlet is formed in the first end face F1 of the first member 161. In this embodiment, the outlet is a first outlet 164. The first outlet 164 penetrates the first member 161 in the first direction (Z direction). The first outlet 164 is connected to the bottom of the first groove 163 in the first end face F1.

[0061] The first discharge port 164 is in communication with the first compression chamber 26. The first discharge port 164 is capable of discharging the refrigerant compressed in the first compression chamber 26. The first discharge port 164 discharges the refrigerant compressed between the first member 161 and the second member 178. In the present embodiment, the compressed refrigerant is discharged into the internal space of the first groove 163.

[0062] A discharge valve 165 is provided in the first discharge port 164. The first discharge port 164 is opened and closed by the discharge valve 165. A gap 169 communicating with the first groove 163 is provided in an outer peripheral surface 168 of the first member 161. The refrigerant discharged from the first discharge port 164 can be discharged from the gap 169 in a direction perpendicular to the first direction (Z direction).

[0063] A second intake port 180 is provided in the second member 178 of the middle side plate 160. The second intake port 180 penetrates the second member 178 in the first direction (Z direction).

[0064] The middle side plate 160 discharges the compressed refrigerant from the first discharge port 164 between the first member 161 and the second member 178 .

[0065] If a discharge port were provided on the outer periphery of the first cylinder 125, the shape of the first cylinder 125 would likely become complex. Furthermore, if the middle side plate 160 were formed from a single member and the discharge path 3 were provided inside the middle side plate 160, it would be difficult to assemble components such as a discharge valve to the discharge port. Therefore, it is desirable to simplify the shape of the first cylinder 125 by providing the discharge path 3 inside the middle side plate 160, as in the configuration of the middle side plate 160 according to the present embodiment, while making the middle side plate 160 a multiple-component configuration including the first member 161 and the second member 178, thereby making it easier to assemble the discharge valve 165 to the first discharge port 164.

[0066] A second discharge port 192 is provided in the rear side plate 190. The second discharge port 192 penetrates the rear side plate 190 in the first direction (Z direction). The second discharge port 192 is opened and closed by a discharge valve 193.

[0067] The suction path 2 is composed of a path through which the refrigerant flows from the suction port 13 of the case 10 to the first suction port 143, and a path through which the refrigerant flows from the first suction port 143 in the compression mechanism 20 to the first compression chamber 26 and the second compression chamber 27.

[0068] The discharge path 3 is composed of a path through which refrigerant flows from the first compression chamber 26 in the compression mechanism 20 to the first discharge port 164, a path through which refrigerant flows from the second compression chamber 27 to the second discharge port 192, and a path through which refrigerant flows from the first discharge port 164 and the second discharge port 192 to the oil separator 40.

[0069] The suction path 2 includes a first suction path 4 and a second suction path 5. The discharge path 3 includes a first discharge path 6 and a second discharge path 7.

[0070] The first suction path 4 is a path that introduces refrigerant into the first compression chamber 26. The first suction path 4 introduces the refrigerant that has flowed into the inside of the case 10 from the suction port 13 into the first compression chamber 26 via the first suction port 143.

[0071] The first discharge path 6 is a path that discharges the refrigerant compressed in the first compression chamber 26. The first discharge path 6 passes through a first discharge port 164 and a gap 169 and is connected to a first communication hole 16 of the case 10, which will be described later. The first discharge path 6 connects the first compression chamber 26 and the oil separator 40.

[0072] The second suction path 5 is a path that introduces refrigerant into the second compression chamber 27. The second suction path 5 branches off from the first suction path 4 at the first suction port 143. The second suction path 5 introduces refrigerant into the second compression chamber 27 via the first suction port 143, the communication holes 132 and 170, and the second suction port 180.

[0073] The second discharge path 7 is a path that discharges the refrigerant compressed in the second compression chamber 27. The second discharge path 7 passes through the second discharge port 192 and is connected to the first communication hole 16 of the case 10. The second discharge path 7 connects the second compression chamber 27 and the oil separator 40.

[0074] The above-described suction path 2 and discharge path 3 create a pressure difference in the refrigerant inside the case 10. As shown in Fig. 3, a suction pressure region 2A is defined within the case 10, where the suctioned refrigerant exists. Also, a discharge pressure region 3A is defined within a portion of the inside of the case 10, where the refrigerant discharged from the compression chamber exists between the inner circumferential surface 15 of the case 10 and the outer circumferential surface of the compression mechanism 20.

[0075] The suction pressure region 2A is an internal space of the case 10 including a path through which the refrigerant flows from the suction port 13 of the case 10 to the first suction port 143 of the front side plate 140. The suction pressure region 2A is in communication with the suction path 2.

[0076] The discharge pressure region 3A is a space between the inner circumferential surface 15 of the case 10 and the outer circumferential surface of the compression mechanism 20. The discharge pressure region 3A includes a part of the path through which the refrigerant flows from the first discharge port 164 and the second discharge port 192 to the oil separator 40. The discharge pressure region 3A is in communication with the discharge path 3.

[0077] The front side plate 140 divides the suction pressure region 2A and the discharge pressure region 3A so that they are aligned in the first direction (Z direction). The front side plate 140 is configured to withstand the pressure of the discharge pressure region 3A. Therefore, the front side plate 140 is thicker than the rear side plate 190 in the first direction (Z direction).

[0078] Specifically, the front side plate 140 has a thickness T1 in a portion other than the outer circumferential portion 141 and the first bearing portion 142. The thickness T1 is the thickness between one end face and the other end face of the front side plate 140 at a position aligned with the cylinder in the first direction (Z direction). The rear side plate 190 has a thickness T2 in a portion other than the second bearing portion 191. The thickness T2 is the minimum thickness of the rear side plate 190. The thickness T1 of the front side plate 140 is greater than the thickness T2 of the rear side plate 190.

[0079] FIG. 6 is a cross-sectional view of the rolling piston compressor of FIG. 1, seen from the direction of the arrows along line VI-VI.

[0080] As shown in Figure 6, a first communication hole 16 and an inner diameter portion 19 are provided in a thick portion of the case 10. The first communication hole 16 connects the discharge pressure region 3A with the inner diameter portion 19. The inner diameter portion 19 extends in the Y direction. The inner diameter portion 19 constitutes a part of the discharge path 3.

[0081] The oil separator 40 is in communication with the discharge pressure region 3A via the first communication hole 16 and the inner diameter portion 19. The oil separator 40 has a cylindrical portion 41. The cylindrical portion 41 is disposed inside the inner diameter portion 19. The cylindrical portion 41 is disposed opposite the direction in which the refrigerant is discharged from the first communication hole 16.

[0082] When the refrigerant mixed with lubricating oil is discharged onto the outer peripheral surface of cylindrical portion 41, the momentum of the discharge causes the refrigerant mixed with lubricating oil to circulate between the outer peripheral surface of cylindrical portion 41 and inner diameter portion 19, and the lubricating oil is centrifuged from the refrigerant. The refrigerant is discharged from discharge port 14 to the outside of rolling piston compressor 1. Meanwhile, the lubricating oil moves downward in the Y direction (direction DR1 in FIG. 6 ) along inner diameter portion 19.

[0083] The lubricating oil is supplied to a lubricating oil supply path 8 that communicates with the inner diameter portion 19. The lubricating oil is supplied to sliding positions of the compression mechanism 20 by the lubricating oil supply path 8. Specifically, the lubricating oil is stored in an oil reservoir 28 (see FIG. 3 ) provided in the front side plate 140 from the lubricating oil supply path 8, and the lubricating oil is supplied to sliding positions of the compression mechanism 20 from the oil reservoir 28.

[0084] The following describes in detail the configuration of the middle side plate 160. Fig. 7 is a perspective view showing the configuration of a first member of the middle side plate according to one embodiment of the present disclosure.

[0085] 7, a groove 177 is formed in at least one of the first end face F1 of the first member 161 and the second end face of the second member on the first member side. In this embodiment, the groove 177 is formed in the first member 161 out of the first member 161 and the second member.

[0086] The maximum thickness T3 of the first member 161 in the first direction (Z direction) is greater than the maximum thickness of the second member 178. Therefore, when the first member 161 and the second member 178 are made of the same material, the first member 161 has higher rigidity than the second member 178.

[0087] When viewed from the first direction (Z direction), the groove portion 177 is formed in an arc shape so as to overlap with the second compression chamber 27. Note that the shape of the groove portion 177 is not limited as long as at least a portion of the groove portion 177 is disposed within an intermediate pressure region R13, to which an intermediate pressure, which will be described later, may be applied.

[0088] The refrigerant drawn through the suction path 2 flows into the groove 177. Specifically, the groove 177 is in communication with the communication hole 170 through which the refrigerant before compression flows in the suction path 2. A portion of the refrigerant before compression flowing through the communication hole 170 flows into the groove 177.

[0089] Here, a rolling piston compressor according to a comparative example will be described. The rolling piston compressor according to the comparative example differs from the rolling piston compressor 1 according to an embodiment of the present disclosure in that the middle side plate does not have a groove, and therefore, description of the configuration that is similar to that of the rolling piston compressor 1 according to an embodiment of the present disclosure will not be repeated.

[0090] FIG. 8 is a side view showing the configuration of a first member of a middle side plate included in a rolling piston compressor according to a comparative example.

[0091] As shown in FIG. 8, in the rolling piston compressor according to the comparative example, no groove is provided in the first member 961 of the middle side plate.

[0092] The inside of first groove 163 is a high-pressure atmosphere where compressed refrigerant exists. The compressed refrigerant is supplied to the internal space of case 10 through gap 169. At this time, stress due to the pressure of the compressed refrigerant is applied to the first end face F1 of first member 961 and the second end face of the second member. This is expected to cause deformation of the first end face F1 of the first member or the second end face of the second member.

[0093] When the first member 961 or the second member is deformed, the refrigerant inside the first groove 163 communicates with the internal space of the inner circumferential surface 162. The internal space of the inner circumferential surface 162 is in a low-pressure atmosphere isolated from the discharge path 3. Therefore, the internal space of the inner circumferential surface 162 becomes an intermediate pressure as the high-pressure refrigerant that has flowed in from the first groove 163 mixes with the low-pressure atmosphere.

[0094] The intermediate pressure causes minute deformation in the first end face F1 of the first member or the second end face F2 of the second member, and is expected to spread radially from the inner periphery of the first end face F1 of the first member or the second end face F2 of the second member.

[0095] Here, a circular imaginary region R90 including an area that can be an intermediate pressure atmosphere is schematically defined. Within the imaginary region R90, there are a high pressure region R91, a low pressure region R92, and an intermediate pressure region R93.

[0096] The high-pressure region R91 is located in the first groove 163 and is a region where compressed refrigerant exists. The low-pressure region R92 is located in the communication hole 170 and is a region where refrigerant exists before being compressed. The intermediate-pressure region R93 is a region where refrigerant in an intermediate-pressure atmosphere exists.

[0097] 9 is a cross-sectional view showing the results of a simulation analysis of deformation of the second member of the middle side plate 960 when refrigerant pressure is applied to the second member from the first member side according to the comparative example. In FIG. 9, the darker portions of the second member 978 of the middle side plate 960 show high stress.

[0098] 9, the second member 978 overlapping with the imaginary region R90 is subjected to stress in the first direction (Z direction) at the second end surface F2 due to the refrigerant pressure P9. The second end surface F2 is subjected to high stress near the center of the imaginary region R90.

[0099] The second member 978 also contacts the second compression chamber 27 at a third end face F3 opposite the second end face F2. Therefore, the third end face F3 of the second member 978 is mainly disposed in a low-pressure atmosphere where the refrigerant before compression is present.

[0100] When stress is applied to the second end face F2, the pressure difference between the second end face F2 and the third end face F3 causes the second member 978 to deform in a direction away from the first member 961 (direction DR2 in FIG. 9 ). The second member 978 deforms, particularly in a direction in which the inner circumferential surface 979 deforms away from the first member 961. With reference to the arrangement of the configuration of the rolling piston type compressor 1 according to this embodiment shown in FIG. 3 , the second member 978 according to the comparative example is prone to deformation at a portion that abuts against the space on the inner circumferential surface of the second cylinder 152, including the second compression chamber 27.

[0101] 10 is a side view of the first member of the middle side plate of FIG. 7 as viewed from the direction of the arrow X. FIG.

[0102] 10 , when assuming the pressure distribution of the refrigerant between the first end face F1 and the second end face F2 of the present embodiment, a virtual region R10 is defined as a circular region including a region that can be an intermediate pressure atmosphere, within a range similar to that of the virtual region R90 of the comparative example.

[0103] Within the virtual region R10, there exist a high pressure region R11, a low pressure region R12, and an intermediate pressure region R13.

[0104] The low-pressure region R12 in the present embodiment includes a first region R15 and a second region R16. The first region R15 is a region where the communication hole 170 is located. The second region R16 is a region where the groove portion 177 is located. The low-pressure region R12 in the present embodiment has a larger area than the low-pressure region R92 in the comparative example by the amount of the second region R16 where the groove portion 177 is located.

[0105] FIG. 11 is a cross-sectional view showing a state in which the pressure of the compressed refrigerant is applied to the second member of the middle side plate from the first member side.

[0106] 10 and 11 , pressure P1 is applied to second end surface F2. Because the pressure of the refrigerant flowing into groove portion 177 is lower than the pressure of the refrigerant discharged from first discharge port 164, the maximum stress imposed on second end surface F2 of second member 178 by refrigerant pressure P1 is reduced.

[0107] Specifically, the pressure P1 is lower than the pressure P9 because the low-pressure region R12 according to the present embodiment has a larger area than the low-pressure region R92 according to the comparative example. That is, the pressure P1 is lower than the pressure P9 because the area of ​​the low-pressure region R12, which has a lower pressure than the high-pressure region R11, is larger compared to the comparative example. This reduces the stress applied to the second end surface F2 by the pressure P1 compared to the comparative example. As a result, deformation of the second member 178 can be suppressed.

[0108] In compression mechanism 20, in order to ensure slidability between components while efficiently compressing refrigerant in the compression chamber, gaps are provided at sliding locations taking into consideration deformation of the components, etc. In the rolling piston compressor according to the comparative example, the gap in the first direction (Z direction) between second member 978 and second piston 150 that constitutes second compression chamber 27 is, for example, 20 μm, taking into consideration deformation of second member 978.

[0109] On the other hand, in the rolling piston compressor 1 of the present embodiment, deformation of the second member 178 is suppressed compared to the comparative example, and therefore it is not necessary to set a gap in anticipation of deformation of the second member 178. This makes it possible to reduce the gap that was set in consideration of deformation of the second member 178. In the rolling piston compressor 1 of the present embodiment, the gap in the first direction (Z direction) between the second member 178 and the second piston 150 is, for example, 10 μm.

[0110] In the rolling piston compressor 1 according to the embodiment of the present disclosure, a groove 177 into which refrigerant drawn from the suction path 2 flows is formed in at least one of the first end face F1 of the first member 161 of the middle side plate 160 and the second end face F2 of the second member 178. Because the pressure of the refrigerant flowing into the groove 177 is lower than the pressure of the refrigerant discharged from the first discharge port 164, the maximum stress imposed on the second end face F2 of the second member 178 by the refrigerant pressure P1 is reduced, thereby suppressing deformation of the second member 178. This reduces the gap provided between the second piston 150 and the second member 178. As a result, leakage of compressed refrigerant in the second compression chamber 27 from the gap is suppressed, thereby providing a highly efficient rolling piston compressor 1.

[0111] In the rolling piston compressor 1 according to an embodiment of the present disclosure, a groove 177 into which refrigerant drawn from the suction path 2 flows is provided in at least one of the first end face F1 of the first member 161 and the second end face F2 of the second member 178, thereby suppressing deformation of the second member 178. This eliminates the need to use an expensive, high-strength material for the second member 178, and by using an inexpensive material for the second member 178, it is possible to provide an inexpensive rolling piston compressor 1. Furthermore, while high-strength materials generally have a high specific gravity and make the rolling piston compressor heavy, the second member 178 can be made of a material with a low specific gravity and low strength, thereby providing a lightweight rolling piston compressor 1.

[0112] In the rolling piston compressor 1 according to an embodiment of the present disclosure, the maximum thickness T3 of the first member 161 in the first direction (Z direction) is set to be thicker than the maximum thickness of the second member 178, and the grooves 177 are formed only in the first member 161. This makes it possible to suppress the effects of deformation of the first member 161 due to the reduced thickness caused by the provision of the grooves 177. It also makes it possible to suppress a decrease in the rigidity of the second member 178, which is prone to deformation under the pressure P1 of the refrigerant. Furthermore, because the number of parts used to form the grooves 177 can be reduced, the processing costs are reduced, and the grooves 177 can be formed inexpensively.

[0113] In the rolling piston compressor 1 according to the embodiment of the present disclosure, the groove 177 is formed in an arc shape so as to overlap with the second compression chamber 27 when viewed from the first direction (Z direction), thereby making it possible to suppress deformation of the portion of the second member 178 that overlaps with the second compression chamber 27 in the first direction (Z direction). This makes it possible to reduce the gap between the second member 178 and the second piston 150 at the location where the second member 178 contacts the second compression chamber 27, thereby suppressing leakage of the compressed refrigerant in the second compression chamber 27 from the gap, making it possible to provide a highly efficient rolling piston compressor 1.

[0114] The rolling piston compressor according to the present disclosure may include a two-stage compression mechanism in which the refrigerant compressed by the first compression section is supplied to the second compression section and further compressed.

[0115] Furthermore, the configuration of the groove portion 177 in the present disclosure is intended to reduce the maximum stress imposed on the second end face F2 of the second member 178 by the refrigerant pressure P1, and is not intended to reduce the stress acting from the first end face F1 to the second end face F2 due to the axial force that restrains the compression mechanism 20 in the first direction (Z direction).

[0116] It should be noted that the above-described embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present disclosure should not be interpreted solely by the above-described embodiments. Furthermore, all modifications within the scope and meaning equivalent to the claims are included. In the description of the above-described embodiments, combinable configurations may be combined with each other.

[0117] DESCRIPTION OF SYMBOLS 1 Rolling piston type compressor 2 Suction path 2A Suction pressure region 3 Discharge path 3A Discharge pressure region 4 First suction path 5 Second suction path 6 First discharge path 7 Second discharge path 8 Lubricating oil supply path 10 Case 11 First case 12 Second case 13 Suction port 14 Discharge port 15 Inner peripheral surface 16 First communication hole 19 Inner diameter portion 20 Compression mechanism 21 Rotating shaft 22 First compression section 23 Second compression section 25 Plate member 26 First compression chamber 27 Second compression chamber 28 Oil storage chamber 30 Motor 31 Stator 32 Rotor 33 Inner peripheral surface 40 Oil separator 41 Cylindrical portion 110 Fixed portion 111 First shaft portion 112 Second shaft portion 113 Third shaft portion 114 First eccentric shaft portion DESCRIPTION OF SYMBOLS 115 Second eccentric shaft portion 120 First piston 121, 168 Outer peripheral surface 122 First vane 123 Tip portion 124 Side portion 125 First cylinder 126, 162, 179, 979 Inner peripheral surface 127 Vane groove 128 Through hole 129 Elastic member 130 Plate-shaped member 131 Fastening member 132, 170 Communication hole 140 Front side plate 141 Outer peripheral portion 142 First bearing portion 143 First intake port 150 Second piston 151 Second vane 152 Second cylinder 160, 960 Middle side plate 161, 961 First member 163 First groove 164 First discharge port (discharge port) 165, 193 Discharge valve 169 Gap 177 Groove portion 178, 978 Second member 180 Second intake port 190 Rear side plate 191 Second bearing portion 192 Second discharge port C Axis center F1 First end face F2 Second end face P1, P9 Pressure R10, R90 Virtual region R11, R91 High pressure region R12, R92 Low pressure region R13, R93 Intermediate pressure region R15 First region R16 Second region

Claims

1. A compressor comprising: a case having an intake path and a discharge path; and a compression mechanism housed in the case and capable of compressing refrigerant drawn through the intake path and discharging the refrigerant to the discharge path, wherein the compression mechanism comprises: a rotary shaft having an axis extending in a first direction; a first piston rotatable in an eccentric state with respect to the axis as the rotary shaft rotates; a first vane abutting against the first piston in a direction intersecting the first direction; a first cylinder housing the first piston and the first vane and defining a first compression chamber between the first piston and the first vane for compressing the refrigerant; a front side plate abutting against the first cylinder in the first direction and in contact with the first compression chamber; a second piston spaced from the first piston and positioned on the opposite side of the first piston from the side on which the front side plate is positioned in the first direction, and rotatable in an eccentric state with respect to the axis as the rotary shaft rotates; and a second vane abutting against the second piston in a direction intersecting the first direction. the compressor includes: a second cylinder that accommodates the second piston and the second vane, and defines a second compression chamber that compresses a refrigerant between the second piston and the second vane; a rear side plate that abuts against the second cylinder from the side opposite to the side where the front side plate is disposed in the first direction and that abuts against the second compression chamber; and a middle side plate that is disposed between the first cylinder and the second cylinder in the first direction and that separates the first compression chamber from the second compression chamber, the middle side plate having: a first member that extends in a direction intersecting the first direction and abuts against the first cylinder in the first direction; and a second member that extends in a direction intersecting the first direction and abuts against the second cylinder and the first member in the first direction, and a discharge port that communicates with the first compression chamber and is able to discharge the refrigerant compressed in the first compression chamber is formed in a first end face of the first member that faces the second member, the discharge port being in communication with the first compression chamber and capable of discharging the refrigerant, a groove portion into which the refrigerant drawn through the suction path flows is formed in at least one of the first end surface of the first member and the second end surface of the second member on the first member side,a pressure of the refrigerant flowing into the groove portion being lower than a pressure of the refrigerant discharged from the discharge port, thereby reducing a maximum stress imposed on the second end surface of the second member by the pressure of the refrigerant.

2. A rolling piston type compressor according to claim 1, wherein the maximum thickness of said first member in said first direction is greater than the maximum thickness of said second member, and said groove portion is formed in said first member.

3. A rolling piston type compressor according to claim 1 or 2, wherein the groove portion is formed in an arc shape so as to overlap with the second compression chamber when viewed from the first direction.

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