Rotary compressor

Abstract

In a rotary compressor, this aims to avoid increased leakage losses and suppress damage during liquid compression. [Solution] The compressor (10) includes a compression mechanism (50, 50a, 50b, 50c). The compression mechanism includes a first roller (60, 60a) and a first vane (70, 70a), a first bush (61, 62, 61a, 62a) that supports the first vane, a first cylinder (51, 51a) having a first cylinder chamber (55, 85) in which the first roller rotates eccentrically and a first vane chamber (63, 63a) in which the first bush moves, and a first plate and a second plate (52a, 53a, 84) at each end thereof. The first bush includes a second bush member (62, 62a) on the discharge side. The first sliding surface (53b, 84, 84c) on the first cylinder side of the second plate has a first recess (81, 81a) that is recessed further than the sliding surface and can accommodate the second bush member (62, 62a).

Description

Technical Field

[0001] The present disclosure relates to a rotary compressor. A rotary compressor is a compressor that compresses gas in a compression chamber formed in a cylinder by eccentrically rotating a roller in the cylinder. A rotary compressor generally has a vane for partitioning the compression chamber.

Background Art

[0002] As a device for compressing a fluid, there is a rotary compressor. When a rotary compressor is incorporated into a refrigeration cycle device and used for gas compression, compression in a state where liquid refrigerant exists in the cylinder (liquid compression) may occur depending on the operating conditions. When liquid compression occurs, the internal pressure of the compression chamber rises rapidly, which may cause damage to the device.

[0003] As a countermeasure to this problem, an accumulator is provided. Further, Patent Document 1 discloses providing an overload avoidance mechanism using a coil spring or the like in a rotary compressor not provided with an accumulator. In the configuration of Patent Document 1, an end plate member is pressed against the cylinder using an elastic body such as a coil spring. When an overload occurs, the end plate member moves to create a gap between the cylinder and the inner pressure is released into the internal space of the compressor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the structure of Patent Document 1, when liquid is compressed, the end plate member moves to release internal pressure, and then the end plate member returns to its original position by an elastic body. However, because the end plate member moves, there is a high possibility that misalignment (misalignment) will occur during the return process. If misalignment occurs, the seal between the end plate member and the cylinder will fail, leading to increased leakage loss.

[0006] The purpose of this disclosure is to realize a rotary compressor that can suppress damage to the device under liquid compression conditions. [Means for solving the problem]

[0007] A first aspect of this disclosure is a rotary compressor (10) comprising a casing (11) having a cylindrical body (12) for storing lubricating oil, a compression mechanism (50, 50a, 50b, 50c) fixed within the casing (11) for compressing a refrigerant, and a drive shaft (30) disposed within the casing (11) for driving the compression mechanism (50, 50a, 50b, 50c). The compression mechanism (50, 50a, 50b, 50c) comprises a first roller (60, 60a), a first vane (70, 70a) formed integrally with the first roller (60, 60a), a pair of first bushes (61, 62, 61a, 62a) that slidably support the first vane (70, 70a), and a first cylinder chamber (55, 85) in which the first roller (60, 60a) rotates eccentrically. The device comprises a first cylinder (51, 51a) having a first vane chamber (63, 63a) in which first vanes (70, 70a) and first bushes (61, 62, 61a, 62a) move, a first plate (52a, 53a, 84) formed on one end of the first cylinder (51), and a second plate (52a, 53a, 84) formed on the other end of the first cylinder (51). The first bushes (61, 62, 61a, 62a) include a first bush member (61, 61a) arranged on the suction side and a second bush member (62, 62a) arranged on the discharge side. On the side of the second plate (52a, 53a, 84) facing the first cylinder (51, 51a), there is a first sliding surface (53b, 84, 84c) that slides with the first roller (60, 60a), and a first recess (81, 81a) that can accommodate the second bushing member (62, 62a) and is recessed compared to the sliding surface (53b, 84, 84c).

[0008] In the first embodiment, when liquid compression occurs in the first cylinder chamber (55, 85), the second bush member (62, 62a) is housed in the first recess (81, 81a). This creates a pressure escape path on the side of the second bush member (62, 62a) opposite to the first recess (81, 81a), thus preventing damage due to abnormal pressure.

[0009] A second aspect of the present disclosure is the first aspect, wherein the first plate (52a, 53a, 84) has discharge ports (57, 57a) for discharging compressed refrigerant.

[0010] In the second embodiment, the invention is applied to a rotary compressor (10) equipped with discharge ports (57, 57a).

[0011] A third aspect of the present disclosure further comprises a first elastic body (91) provided in the first recess (81, 81a) in the first aspect.

[0012] In the third embodiment, the elastic force of the first elastic body (91) can be used to bias the second bushing members (62, 62a) so that they return to their original positions.

[0013] A fourth aspect of this disclosure is the third aspect, wherein the first elastic body (91) is arranged at a distance from the second bushing members (62, 62a).

[0014] In the fourth embodiment, the second bushing members (62, 62a) are not initially prevented from being housed in the first recesses (81, 81a), and the first elastic body (91) can be used to return the high-pressure side bushing members (62, 62a) to their original position.

[0015] A fifth aspect of the present disclosure is, in any one of the first to third aspects, the second plate (52a, 53a, 84) has through holes (82, 82a) that connect the first recess to the lubricating oil reservoir (18) in the casing (11).

[0016] In the fifth embodiment, since lubricating oil can enter and exit between the through holes (82, 82a), the first recesses (81, 81a), and the storage portion (18), the second bushing members (62, 62a) can be housed in the first recesses (81, 81a) and returned to their original positions when compressed.

[0017] A sixth aspect of the present disclosure is, in the fifth aspect, the drive shaft (30) extends vertically, lubricating oil is stored at the bottom of the casing (11), and the through holes (82, 82a) extend vertically.

[0018] In the sixth aspect, it can be effectively restored by pushing up the second bush member (62, 62a) through the through holes (82, 82a) extending in the vertical direction.

[0019] In the seventh aspect of the present disclosure, in the fifth aspect, the drive shaft (30) extends in the vertical direction, the lubricating oil is stored at the bottom of the casing (11), and the through holes (82, 82a) extend in the radial direction of the drive shaft (30).

[0020] In the seventh aspect, the second bush member (62, 62a) can be restored by the lubricating oil in the relatively upper part of the storage portion (18). The lubricating oil tends to have a higher viscosity towards the upper part, and the higher the viscosity of the lubricating oil, the higher the effect of restoring the second bush member (62, 62a).

[0021] In the eighth aspect of the present disclosure, in any one of the first to seventh aspects, the depth of the first recess (81, 81a) is 1 / 2 or less of the height of the vane (70, 70a).

[0022] In the ninth aspect of the present disclosure, in any one of the first to seventh aspects, the depth of the first recess (81, 81a) is 1 / 4 or less of the height of the vane (70, 70a).

[0023] In the tenth aspect of the present disclosure, in any one of the first to seventh aspects, the depth of the first recess (81, 81a) is 0.5 mm or more and 5 mm or less.

[0024] In the eighth to tenth aspects, after releasing the pressure during hydraulic compression, the high-pressure side bush member (62, 62a) can be more reliably restored.

[0025] In the eleventh aspect of the present disclosure, in any one of the first to tenth aspects, when viewed from the axial direction of the drive shaft (30), the first recess (81, 81a) has a shape that includes the entire movement range of the second bush member (62, 62a).

[0026] In the 11th aspect, the moving second bush members (62, 62a) can be accommodated in the first recesses (81, 81a) at any position.

[0027] A 12th aspect of the present disclosure is, in the 11th aspect, when viewed from the axial direction of the drive shaft (30), the first recesses (81, 81a) have portions overlapping the first cylinder chambers (55, 85).

[0028] In the 10th aspect, the second bush members (62, 62a) can enter the first cylinder chambers (55, 85).

[0029] A 13th aspect of the present disclosure is, in any one of the 1st to 12th aspects, the first bush members (61, 61a) and the second bush members (62, 62a) each have an arcuate first surface (62) formed along the vane chambers (63, 63a) and a second surface (69) facing the cylinder chambers (55, 85).

[0030] In the 13th aspect, when hydraulic compression occurs and the first bush members (61, 61a) are accommodated in the first recesses (81, 81a), a pressure relief path is configured in a portion corresponding to the second surface (69).

[0031] A fourteenth aspect of the present disclosure, in any one of the first to thirteenth embodiments, further comprises a compression mechanism (50, 50a, 50b, 50c) including a second roller (60, 60a), a second vane (70, 70a) integrally formed with the second roller (60, 60a), a pair of second bushes (61, 62, 61a, 62a) slidably supporting the second vane (70, 70a), a second cylinder (51, 52a) of the second plate (52a, 53a, 84) positioned on the opposite side of the first cylinder (51, 52a), and a third plate (52a, 53a, 84) of the second cylinder (51, 52a) positioned on the opposite side of the second plate (52a, 53a, 84). The second cylinder (51, 52a) has a second cylinder chamber (55, 85) in which the second roller (60, 60a) rotates eccentrically, and a second vane chamber (63, 63a) in which the second vane (70, 70a) and the second bush (61, 62, 61a, 62a) move. The second bush (61, 62, 61a, 62a) includes a third bush member (61, 61a) located on the intake side and a fourth bush member (62, 62a) located on the discharge side. On the side of the second plate (52a, 53a, 84) facing the second cylinder (51, 52a), a second sliding surface (53b, 84, 84c) that slides with the second roller (60, 60a) and a second recess (81, 81a) that is recessed further than the second sliding surface (53b, 84, 84c) and capable of accommodating the fourth bushing member (62, 62a) are further formed.

[0032] In the 14th embodiment, the effect of avoiding damage due to liquid compression can be achieved in each cylinder of the rotary compressor (10) having multiple cylinders.

[0033] A fifteenth aspect of the present disclosure further comprises a second elastic body (91a) provided in the second recess (81, 81a) in the fourteenth aspect.

[0034] In the 15th embodiment, the elastic force of the second elastic body (91) can be used to bias the fourth bushing member (62, 62a) so that it returns to its original position. [Brief explanation of the drawing]

[0035] [Figure 1] Figure 1 is a schematic diagram showing the configuration of a refrigeration system including a rotary compressor according to the present disclosure. [Figure 2] Figure 2 is a schematic cross-sectional view showing a rotary compressor according to an embodiment of the present disclosure. [Figure 3] Figure 3 is a schematic plan view showing the piston and its operation provided in the rotary compressor of this disclosure. [Figure 4] Figure 4 is a magnified view of the vane chamber and bush area in the compression mechanism of this disclosure. [Figure 5] Figure 5 is a schematic diagram showing a longitudinal section of the compression mechanism of this disclosure. [Figure 6] Figure 6 is a schematic diagram showing a cross-section of the compression mechanism of this disclosure. [Figure 7] Figure 7 shows the range of movement of the high-pressure side bushing member and the planar shape of the first recess in the compression mechanism of this disclosure. [Figure 8] Figure 8 is a schematic diagram showing a longitudinal section of the compression mechanism of the first modified example of the present disclosure. [Figure 9] Figure 9 is a schematic diagram showing a longitudinal section of the compression mechanism of a second modified example of the present disclosure. [Figure 10] Figure 10 is a schematic diagram showing a longitudinal section of another configuration in the compression mechanism of the second modified example of the present disclosure. [Figure 11] Figure 11 is a schematic diagram showing a longitudinal section of a compression mechanism of a third modified example of the present disclosure. [Modes for carrying out the invention]

[0036] Embodiments of the present invention will be described in detail below with reference to the drawings. The following description of preferred embodiments is essentially illustrative and is not intended to limit the present invention, its applications, or its uses.

[0037] (Refrigeration equipment) As shown in Figure 1, the compressor (1) of this disclosure is applied to a refrigeration system (100). The refrigeration system (100) is, for example, an air conditioning system that provides air conditioning for a room. The refrigeration system (100) has an outdoor unit (7) located outside and an indoor unit (8) located inside. The outdoor unit (7) houses the compressor (1), a four-way switching valve (3), an outdoor heat exchanger (4), and an expansion valve (5). The indoor unit (8) houses an indoor heat exchanger (6).

[0038] The refrigeration system (100) includes a refrigerant circuit (9). A compressor (1), a four-way switching valve (3), an outdoor heat exchanger (4), an expansion valve (5), and an indoor heat exchanger (6) are connected to the refrigerant circuit (9). The refrigeration cycle is performed by the flow of refrigerant through the refrigerant circuit (9).

[0039] (Overall configuration of the compressor) Figure 2 is a longitudinal cross-sectional view of the compressor (10) according to this embodiment. The compressor (10) according to this embodiment is a fully enclosed rotary compressor. The compressor (10) is connected to a refrigerant circuit (not shown) filled with refrigerant. A vapor compression type refrigeration cycle is carried out in the refrigerant circuit. That is, in the refrigerant circuit, the refrigerant compressed by the compressor (10) is condensed in a condenser, depressurized by an expansion valve, evaporated in an evaporator, and then drawn back into the compressor (10).

[0040] The compressor (10) comprises a casing (11), an electric motor (20) housed inside the casing (11), a drive shaft (30) connected to the electric motor (20), and a compression mechanism (50) driven by the drive shaft (30).

[0041] (Casing) The casing (11) is composed of a vertically elongated cylindrical sealed container. The casing (11) has a body (12), a lower end plate (13), and an upper end plate (14). The body (12) is formed in a cylindrical shape that extends vertically, with both ends in the axial direction open. The lower end plate (13) is fixed to the lower end of the body (12). The upper end plate (14) is fixed to the upper end of the body (12).

[0042] A suction pipe (15) is fixed through the lower part of the body (12). A discharge pipe (16) is fixed through the upper end plate (14). A terminal (17) for supplying power to the electric motor (20) is attached to the upper end plate (14).

[0043] An oil reservoir (18) is formed at the bottom of the casing (11). The oil reservoir (18) is composed of the lower end plate (13) and the lower inner wall of the body (12). Lubricating oil (refrigeration oil) for lubricating the sliding parts of the compression mechanism (50) and the drive shaft (30) is stored in the oil reservoir (18).

[0044] The inside of the casing (11) is filled with high-pressure refrigerant compressed by the compression mechanism (50). In other words, the compressor (10) is configured in a so-called high-pressure dome shape, where the internal pressure of the internal space (S) of the casing (11) is substantially equal to the pressure of the high-pressure refrigerant.

[0045] (Electric motor) The electric motor (20) is positioned above the compression mechanism (50). The electric motor (20) has a stator (21) and a rotor (22). The stator (21) is fixed to the inner circumferential surface of the body (12) of the casing (11). The rotor (22) penetrates the inside of the stator (21) in the vertical direction. A drive shaft (30) is fixed inside the axial center of the rotor (22). When the electric motor (20) is energized, the drive shaft (30) is rotated together with the rotor (22).

[0046] (Drive shaft) The drive shaft (30) is located on the axis of the body (12) of the casing (11). The drive shaft (30) is rotatably supported by the bearings (41, 42, 43) of the compression mechanism (50).

[0047] The drive shaft (30) has, in order from top to bottom, a main shaft (31), a crankshaft (32), and a secondary shaft (33). The upper part of the main shaft (31) is fixed to the rotor (22) of the electric motor (20). The crankshaft (32) is connected to the lower end of the main shaft (31). The secondary shaft (33) is connected to the lower end of the crankshaft (32). The axis of the main shaft (31) and the axis of the secondary shaft (33) coincide. The axis of the crankshaft (32) is eccentric by a predetermined amount with respect to the axes of the main shaft (31) and the secondary shaft (33). The outer diameter of the crankshaft (32) is larger than the outer diameters of the main shaft (31) and the secondary shaft (33).

[0048] The upper part of the main shaft (31) is fixed to the rotor (22) of the electric motor (20). The lower part of the main shaft (31) is located inside the main shaft side through-hole (52c) of the front head (52). The axial middle part of the main shaft (31) is rotatably supported by the upper main bearing (41). The lower part of the main shaft (31) is rotatably supported by the lower main bearing (42). The upper part of the secondary shaft (33) is located inside the secondary shaft side through-hole (53c) of the rear head (53). The axial middle part of the secondary shaft (33) is rotatably supported by the secondary bearing (43).

[0049] The drive shaft (30) is equipped with an oil supply mechanism (34) for supplying oil to the surrounding area of ​​the crankshaft (32) and the sliding parts of each bearing (41, 42, 43). The oil supply mechanism (34) has an oil pump (35) attached to the lower end of the sub-shaft (33), a main passage (not shown) extending along the axis inside the drive shaft (30), and branch passages (not shown) branching from the main passage to each sliding part.

[0050] (Compression mechanism) As shown in Figure 2, the compression mechanism (50) is located below the electric motor (20). As shown in Figure 2, the compression mechanism (50) is configured in a so-called swing type, in which vanes formed integrally with the rollers oscillate in accordance with the eccentric rotation of the rollers. As shown in Figure 2, the compression mechanism (50) comprises a cylinder (51), a front head (52), and a rear head (53). In the compression mechanism (50), the front head (52) is stacked on the upper end (one axial end) of the cylinder (51), and the rear head (53) is stacked on the lower end (the other axial end) of the cylinder (51). The cylinder (51), the front head (52), and the rear head (53) are integrated via fastening members (not shown). The front head (52) and the rear head (53) constitute a head member.

[0051] The cylinder (51) is fixed to the inner circumferential surface of the lower part of the body (12) of the casing (11). The cylinder (51) is formed in a flat, roughly annular shape, with a cylindrical cylinder chamber (55) in its center. As shown in Figure 2, a radially extending intake port (56) is formed through the cylinder (51). An intake pipe (15) is connected to the intake port (56) so as to communicate with the cylinder chamber (55).

[0052] In the front head (52), a shaft-side through-hole (52c) is formed in the center of the front annular plate portion (52a) and the cylindrical projection portion (52b), through which the shaft (31) passes. An upper main bearing (41) is formed on the inner circumferential surface of the upper end of the shaft-side through-hole (52c). A lower main bearing (42) is formed below the shaft-side through-hole (52c). A discharge port (57) is formed in the front head (52) that communicates with the high-pressure chamber (55b) of the cylinder chamber (55) and passes through it axially. A discharge valve (not shown), such as a reed valve, is provided in the discharge port (57). The discharge valve is configured to open the discharge port (57) when the internal pressure of the high-pressure chamber (55b) becomes greater than the external pressure of the compression mechanism (50) (i.e., the pressure of the internal space (S)). This causes the refrigerant in the high-pressure chamber (55b) to be discharged to the outside (internal space (S)) of the compression mechanism (50), resulting in a discharge stroke.

[0053] The rear head (53) is positioned below the cylinder (51) so as to cover the internal space of the cylinder (51). The rear head (53) has a rear annular plate portion (53a), and a sub-shaft side through-hole (53c) is formed in the radial center portion through which the sub-shaft (33) passes. A sub-bearing (43) is formed on the inner circumferential surface of the sub-shaft side through-hole (53c).

[0054] As shown in Figure 3, the compression mechanism (50) of this embodiment comprises a roller (60), a pair of bushings (61, 62), and a vane (70). The roller (60) is housed in a cylinder chamber (55). The roller (60) is formed in a cylindrical shape, and a crankshaft (32) is fitted inside it.

[0055] The cylinder (51) has a first inner surface and a second inner surface. The cylinder (51) is composed of a vane chamber (63) formed by the first inner surface and a back pressure chamber (64) formed by the second inner surface. The vane chamber (63) is formed adjacent to the cylinder chamber (55) and communicates with the cylinder chamber (55). The vane chamber (63) constitutes a cylindrical space with a substantially circular cross-section. The back pressure chamber (64) is located radially outward from the vane chamber (63) in the cylinder (51). The back pressure chamber (64) constitutes a cylindrical space with a substantially circular cross-section. The end of the back pressure chamber (64) on the cylinder chamber (55) side communicates with the vane chamber (63). The back pressure chamber (64) has a high-pressure atmosphere equivalent to the pressure in the internal space (S) of the casing (11).

[0056] Figure 4 is a magnified view of the area around the vane chamber (63) and bush (61, 62).

[0057] A pair of bushings (61, 62) are fitted inside the vane chamber (63). The pair of bushings (61, 62) consists of one low-pressure side bushing member (61) closer to the low-pressure chamber (55a) (intake port (56)) and one high-pressure side bushing member (62) closer to the high-pressure chamber (55b) (discharge port (57)).

[0058] Each of the pair of bushes (61, 62) is formed in a roughly arched or semicircular cross-section with both ends cut off. In other words, each pair of bushes (61, 62) has an arc-shaped first surface (65) facing the first inner surface of the cylinder (51), a second surface (69) facing the cylinder chamber (55), a third surface (66) facing the vane (70), and a fourth surface (68) facing the back pressure chamber (64).

[0059] The shape of the cross-section perpendicular to the axis (horizontal cross-section) of the first surface (65) is approximately arc-shaped. The shapes of the cross-section perpendicular to the axis (horizontal cross-section) of the second surface (69), third surface (66), and fourth surface (68) are formed to be approximately straight. In this embodiment, the connection between the third surface (66) and the second surface (69) or fourth surface (68) is chamfered.

[0060] The pair of bushes (61, 62) oscillate with their first surfaces (65) sliding against the first inner surface of the cylinder (51) with the center of the vane chamber (63) as their axis. The pair of bushes (61, 62) are positioned in the vane chamber (63) such that their third surfaces (66) face each other. As a result, a vane groove (67) is formed between the third surfaces (66) of the pair of bushes (61, 62). The vane groove (67) has a substantially rectangular cross-section, and a vane (70) is held inside it so as to be able to move back and forth radially.

[0061] The vane (70) is formed in a rectangular parallelepiped or plate shape extending radially outward. The base end (radially inward end) of the vane (70) is connected to the outer circumferential surface of the roller (60). The vane (70) is housed in a vane groove (67) formed between a pair of bushes (61, 62) so as to be able to move back and forth. The tip end (radially outward end) of the vane (70) is located in the back pressure chamber (64).

[0062] The vane (70) constitutes a partition that divides the cylinder chamber (55) into a low-pressure chamber (55a) and a high-pressure chamber (55b). The low-pressure chamber (55a) is the space to the right of the vane (70) in Figure 3 and is in communication with the suction port (56). The high-pressure chamber (55b) is the space to the left of the vane (70) in Figure 3 and is in communication with the discharge port (57).

[0063] In the compression mechanism (50) of this embodiment, for example, the discharge stroke is performed when the rotation angle of the roller (60) is in the range of approximately 180° to approximately 330°. In this discharge stroke, the refrigerant compressed in the high-pressure chamber (55b) is discharged to the outside of the compression mechanism (50) (internal space (S)) through the discharge port (57).

[0064] In Figure 4, there are gaps between the bushings (61, 62), vane (70), and cylinder (51). These gaps are filled with lubricating oil to prevent refrigerant leakage.

[0065] (Compressor operation) The basic operation of the compressor (10) will be explained with reference to Figures 2 and 3.

[0066] When power is supplied from the terminal (17) to the electric motor (20), the electric motor (20) operates and the drive shaft (30) is rotated. The crankshaft (32) of the drive shaft (30) rotates eccentrically, and the roller (60) oscillates in response.

[0067] As shown in Figure 3, in the compression mechanism (50), the outer surface of the roller (60) makes line contact with the inner surface of the cylinder chamber (55) via an oil film, forming a seal. When the roller (60) oscillates inside the cylinder chamber (55), the seal between the roller (60) and the cylinder (51) is displaced along the inner surface of the cylinder chamber (55), changing the volumes of the low-pressure chamber (55a) and the high-pressure chamber (55b). At this time, the vane (70) moves back and forth inside the vane groove (67) in accordance with the oscillating motion of the roller (60), and also oscillates about the axis of the vane chamber (63).

[0068] As the roller (60) oscillates (rotation angle = 0° → 90° → 180° → 270°), the volume of the low-pressure chamber (55a) gradually increases, and the fluid (refrigerant) flowing through the suction pipe (15) is drawn into the low-pressure chamber (55a) from the suction port (56). Next, when this low-pressure chamber (55a) is blocked from the suction port (56), the blocked space forms a high-pressure chamber (55b) (rotation angle = 90°). Next, as the volume of this high-pressure chamber (55b) gradually decreases (rotation angle = 90° → 180° → 270°), the internal pressure of the high-pressure chamber (55b) increases. When the internal pressure of the high-pressure chamber (55b) becomes greater than the pressure of the internal space (S), the discharge stroke takes place. In other words, during the discharge stroke, the reed valve of the discharge port (57) is opened, and the refrigerant in the high-pressure chamber (55b) flows out of the compression mechanism (50) through the discharge port (57). This high-pressure refrigerant flows upward through the internal space of the casing (11) and passes through the core cut (not shown) of the electric motor (20). The high-pressure refrigerant that has flowed out above the electric motor (20) is sent to the refrigerant circuit from the discharge pipe (16).

[0069] (Suppression of liquid compression) In the compression mechanism (50) that operates as described above, a configuration to avoid damage due to liquid compression is described below.

[0070] Figure 5 schematically shows a longitudinal section of the compression mechanism (50). Figure 5 can be described as an enlarged view of the lower part of Figure 2, but it is a cross-section at a different angle centered on the drive shaft (30). Specifically, it corresponds to the cross-section along the VV line in the cross-section of Figure 6.

[0071] Figure 5 shows a front head (52) with a front annular plate portion (52a), a rear head (53) with a rear annular plate portion (53a), and a cylinder (51) that together with these constitutes a cylinder chamber (55). Figure 5 shows the low-pressure chamber (55a) of the cylinder chamber (55). Also shown are a roller (60) and vanes (70) connected thereto, which are positioned in the cylinder chamber (55), and a high-pressure side bushing member (60) of the bushes (61, 62) that hold the vanes (70). The rear annular plate portion (53a) of the rear head (53) has a first sliding surface (53b) that slides against the roller (60). The discharge port (57) is also shown in this cross-section.

[0072] Furthermore, a first recess (81) is formed below the high-pressure side bush member (62) in the rear annular plate portion (53a), which is recessed more than the first sliding surface (53b). The first recess (81) is recessed in the cylinder (51) on the side opposite to the discharge port (57). Below the first recess (81), a through hole (82) is formed that penetrates the rear head (53) in the longitudinal direction. The through hole (82) connects the first recess (81) to the oil reservoir (18) inside the casing (11).

[0073] Due to the pressure inside the casing (11), the first recess (81) is filled with lubricating oil through the through hole (82). When no liquid compression occurs and the compression mechanism (50) is operating normally, the pressure of the lubricating oil causes the high-pressure side bush member (62) to float and is held in place on the first sliding surface (52b). At this time, the high-pressure side bush member (62) and the lower surface of the front annular plate portion (52a) of the front head (52) are sealed by the lubricating oil. Therefore, leakage can be suppressed when the refrigerant in the high-pressure chamber (55b) is compressed and discharged through the discharge port (57).

[0074] In contrast, when the liquid refrigerant is compressed in the compression mechanism (50) (liquid compression occurs), the abnormally high-pressure liquid enters the gaps above and below the high-pressure side bush member (62). At this time, the first recess (81) is in communication with the space inside the casing (11) through the through hole (82), so the pressure applied to the lubricating oil can be released. As a result, the pressure below the high-pressure side bush member (62) is lower than above, creating a pressure difference. Due to this pressure difference, the high-pressure side bush member (62) lowers so that it fits into the first recess (81), and a gap is formed between the high-pressure side bush member (62) and the front annular plate portion (52a). The gap thus formed on the high-pressure side bush member (62) becomes a path for pressure to escape from the high-pressure chamber (55b) to the back pressure chamber (64). In Figure 4, the path (83) passing over the high-pressure side bush member (62) is indicated by an arrow.

[0075] As described above, even if liquid compression occurs, the pressure can be released through the path (83), thus avoiding damage to the compression mechanism (50).

[0076] Subsequently, as pressure escapes through the path (83), the pressure inside the cylinder chamber (55) decreases. As a result, the pressure difference between the upper and lower parts of the high-pressure side bush member (62) decreases, and the high-pressure side bush member (62) returns to its original position due to the pressure of the lubricating oil in the first recess (81). In this case, seal failure, which occurs due to misalignment in conventional structures where the end plate member moves, does not occur. Furthermore, the effects of this disclosure are achieved without increasing the number of parts.

[0077] To enable the above operations, the first recess (81) has a planar shape capable of accommodating the high-pressure side bush member (62). An example of this is shown in Figure 7.

[0078] Figure 7 shows the range of movement of the high-pressure side bushing member (62) in the vane chamber (63). As the roller (60) shown in Figure 3 swings, the high-pressure side bushing member (62) moves between the position shown by the solid line and the position shown by the dashed line in Figure 7. If the first recess (81) is formed in a planar shape that includes the entire range of movement, the high-pressure side bushing member (60) will be securely accommodated in the first recess (81). Furthermore, even when the high-pressure side bushing member (62) is lowered into the first recess (81), the swinging of the roller (60) continues. From this point of view as well, it is desirable that the first recess (81) includes the entire range of movement of the high-pressure side bushing member (62). Note that the first recess (81) exemplified in Figure 7 has a planar shape like a semicircle with both ends cut off, but this is just an example, and other shapes are also acceptable.

[0079] Furthermore, as shown in Figure 7, when viewed from the axial direction of the drive shaft (30), a portion of the high-pressure side bush member (62) enters the cylinder chamber (55). Therefore, the first recess (81) has a portion that overlaps with the cylinder chamber (55).

[0080] (First variation) As a first modification of the present disclosure, a case of a compression mechanism (50) having multiple cylinders (specifically, two cylinders) will be described.

[0081] Figure 8 is a schematic diagram showing a cross-section in the direction of the drive shaft (30) of the compression mechanism (50a) of the first modified example. The compression mechanism (50a) includes a front head (52) and a rear head (53) similar to the compression mechanism (50) illustrated in Figure 5, and a middle plate (84) located between them.

[0082] In the compression mechanism (50) of Figure 5, one cylinder (51) is provided between the front head (52) and the rear head (53), forming a single-cylinder compression device (50). In contrast, in the compression mechanism (50a) of Figure 8, a first cylinder (51) is positioned between the front head (52) and the middle plate (84) to form a first cylinder chamber (55), and a second cylinder (51a) is positioned between the middle plate (84) and the rear head (53) to form a second cylinder chamber (85), resulting in a two-cylinder compression mechanism (50a).

[0083] The configuration of the two cylinders is the same as that described in Figures 3 and 4.

[0084] In other words, the first cylinder (51) comprises a first vane chamber (63) and a first back pressure chamber (64), and a first roller (60), a pair of first bushes (61, 62), and a first vane (70) are arranged inside the first cylinder (51). The first bushes (61, 62) have a first low-pressure side bush member (61) and a first high-pressure side bush member (62). A first discharge port (57) is provided in the front annular plate portion (52a) of the front head (52).

[0085] Furthermore, the second cylinder (51a) includes a second vane chamber (63) and a second back pressure chamber (64a), and a second roller (60a), a pair of second bushes (61a, 62a), and a second vane (70a) are arranged inside the second cylinder (51a). The second bushes (61, 62) have a second low-pressure side bush member (61) and a second high-pressure side bush member (62). A second discharge port (57a) is provided in the rear annular plate portion (53a) of the rear head (53).

[0086] Although a separate plan view of the second cylinder (51a) is not shown, you can simply change the reference numerals in Figure 3 as appropriate (for example, change the first roller (60) to the second roller (60a), and the first cylinder chamber (55) to the second cylinder chamber (85)).

[0087] In the compression mechanism (50) shown in Figure 5, a first recess (81) is formed below the first high-pressure side bush member (62) in the rear annular plate portion (53a) of the rear head (53), and is recessed more than the first sliding surface (53b). Furthermore, a through hole (82) is formed below the first recess (81), which penetrates the rear head (53) in the longitudinal direction.

[0088] In contrast, in the first modified compression mechanism (50a) of Figure 8, instead of the rear head (53), a first recess (81) is provided in the middle plate (84) located below the first cylinder (51). The first recess (81) is recessed more than the sliding surface (84) on the first cylinder (51) side of the middle plate (84). The first recess (81) is recessed on the side of the first cylinder (51) opposite to the first discharge port (57). Furthermore, the first through hole (82) that connects the first recess (81) and the oil reservoir (18) is formed to extend laterally.

[0089] As a result, when liquid compression occurs in the first cylinder (51), the first high-pressure side bush member (62) is housed in the first recess (81), and a path (83) for the pressure to escape is formed on the first high-pressure side bush member (62), similar to Figure 4. Therefore, the first cylinder (51) is effectively protected from damage due to liquid compression.

[0090] Furthermore, in order to provide a path for pressure to escape when liquid compression occurs in the second cylinder (51a), a second recess (81a) is provided above the second high-pressure side bush member (62a) in the middle plate (84). The second recess (81a) is recessed more than the sliding surface (84c) on the second cylinder (51a) side of the middle plate (84). The second recess (81a) is recessed on the side of the second cylinder (51a) opposite to the second discharge port (57a). In addition, a second through hole (82a) is formed to extend laterally, connecting the second recess (81a) and the oil reservoir (18).

[0091] When liquid compression occurs in the second cylinder (51a), the liquid refrigerant, which has become abnormally high pressure, enters the gaps above and below the second high-pressure side bushing member (62a). At this time, the second recess (81a) is in communication with the space inside the casing (11) through the second through hole (82a), so the pressure can escape. As a result, the pressure above the second high-pressure side bushing member (62a) is lower than below, creating a pressure difference. Due to this pressure difference, the second high-pressure side bushing member (62a) rises so that it fits into the second recess (81a), and a gap is formed between the second high-pressure side bushing member (62) and the middle plate (84). The gap formed below the second high-pressure side bushing member (62a) in this way becomes a path for pressure to escape from the second cylinder chamber (85) to the second back pressure chamber (64a). Therefore, the second cylinder (51a) is also protected from damage due to liquid compression.

[0092] In addition, in the first modified example, the first recess (81) and the second recess (81a) have a planar shape that includes the entire range of movement of the first high-pressure side bush member (62) and the second high-pressure side bush member (62a). This is the same as the first recess (81) illustrated in Figure 7.

[0093] Furthermore, in Figure 5, the through-hole (82) penetrates the rear annular plate portion (53a) in the vertical direction. In this case, after the pressure during liquid compression is released, the lubricating oil in the oil reservoir (18) pushes the first high-pressure side bush member (62) from below through the through-hole (82), making it easier to return the first high-pressure side bush member (62), which is housed in the first recess, to the vane chamber (63).

[0094] In contrast, in Figure 8, the through holes (82, 82a) penetrate the middle plate (84) radially (laterally) through the cylinder (51, 51a). The viscosity of the lubricating oil in the oil reservoir (18) tends to be higher at the top. The effect of returning the high-pressure side bush members (62, 62a) to the vane chambers (63, 63a) is greater when the viscosity of the lubricating oil is higher. Therefore, by forming the through holes (82, 82a) to extend laterally, the lubricating oil at a higher position can be used to return the high-pressure side bush members (62, 62a).

[0095] Furthermore, in all of the examples shown in Figures 5 and 8 (and Figures 9 to 11 described below), the depth of the recesses (81, 81a) is preferably 1 / 2 or less of the height of the high-pressure side bush members (62, 62a), and more preferably 1 / 4 or less. In addition, the depth of the recesses (81, 81a) is preferably 0.5 mm or more and 5 mm or less. Such dimensions are desirable from the viewpoint of returning the high-pressure side bush members (62, 62a) after releasing the pressure during liquid compression.

[0096] (Second variation) A second modification of the present disclosure will now be described. Figures 9 and 10 schematically show a cross-section of the compression mechanism (50b) of the second modification in the direction of the drive shaft (30). The compression mechanism (50b) in Figures 9 and 10 has components in common with the compression mechanism (50) shown in Figure 5. Therefore, such common components are denoted by the same reference numerals as in Figure 5, and the differences will be mainly described below.

[0097] In the second modified compression mechanism (50b), an elastic body (91) is provided in the first recess (81). The elastic body (91) may be, for example, a coil spring (91) as shown in Figure 9, a leaf spring (91) as shown in Figure 10, etc. Furthermore, the first through hole (82) that connects the first recess (81) and the oil reservoir (18) is formed to extend laterally.

[0098] The elastic body (91) functions as a biasing means that, by elastic force, returns the high-pressure side bush member (62) from the first recess (81) to its original position. This will be explained below.

[0099] In the compression mechanism (50b), when liquid compression occurs in the first cylinder (51), the high-pressure side bush member (62) moves down to fit into the first recess (81). Subsequently, when the pressure in the cylinder chamber (55) decreases, the high-pressure side bush member (62) returns to its original position.

[0100] In this process, the high-pressure side bush member (62) is subjected not only to the pressure of the lubricating oil in the first recess (81) but also to the elastic force of the elastic body (91). Therefore, the high-pressure side bush member (62) can be returned to its original position more reliably.

[0101] It is preferable that the elastic body (91) is positioned at a distance from the high-pressure side bushing member (62). Therefore, it is preferable that the height of the elastic body (91) is less than the depth of the first recess (81).

[0102] In this configuration, when the compression mechanism (50) operates normally and the high-pressure side bush member (62) is held in place on the first sliding surface (52b), the elastic body (91) is not in contact with the high-pressure side bush member (62). In this state, the elastic force of the elastic body (91) is not applied to the high-pressure side bush member (62). Therefore, at the beginning of liquid compression, the high-pressure side bush member (62) can move down into the first recess (81) without being hindered by the elastic body (91). When the high-pressure side bush member (62) moves down and compresses the elastic body (91), the elastic body (91) generates a force that returns the high-pressure side bush member (62) to its original position. As described above, damage to the compression mechanism (50b) due to liquid compression can be avoided, and the return of the high-pressure side bush member (62) can be made more reliable.

[0103] (Third variation) A third modification of the present disclosure will now be described. Figure 11 is a schematic diagram showing a cross-section of the compression mechanism (50c) of the third modification in the direction of the drive shaft (30). The compression mechanism (50c) in Figure 11 has components in common with the compression mechanism (50a) shown in Figure 8. Therefore, such common components are denoted by the same reference numerals as in Figure 8, and the differences will be mainly explained below.

[0104] The compression mechanism (50c) in Figure 11 further comprises a first elastic body (91) provided in the first recess (81) and a second elastic body (91a) provided in the second recess (81a). The first elastic body (91) and the second elastic body (91a) may be a coil spring, a leaf spring, or the like.

[0105] The first elastic body (91), similar to the second modified example, functions as a biasing means to return the first high-pressure side bushing member (62) from the first recess (81) to its original position. The second elastic body (91a) also functions as a biasing means to return the second high-pressure side bushing member (62a) from the second recess (81) to its original position.

[0106] In the third modified example, when the compression mechanism (50c) is operating normally, it is preferable that the first elastic body (91) is positioned at a distance from the first high-pressure side bushing member (62), and the second elastic body (91a) is positioned at a distance from the second high-pressure side bushing member (62a). This makes it possible to avoid damage to the compression mechanism (50b) due to liquid compression, as in the second modified example, and to make the return of the high-pressure side bushing member (62) more reliable.

[0107] Although embodiments and modifications have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, elements of the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate.

[0108] Furthermore, the designations "1st," "2nd," "3rd," etc., mentioned above are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of those terms. [Industrial applicability]

[0109] As explained above, this disclosure is useful for compressors. [Explanation of Symbols]

[0110] 10 Rotary Compressor 11 Casing 12 Torso 18 Storage section 30 Drive shaft 50, 50a, 50b, 50c Compression mechanism 51,51a Cylinder 52a, 53a, 84 Front annular plate section, rear annular plate section, middle plate (1st plate, 2nd plate, 3rd plate) 53b,84,84c Sliding surface 55,85 Cylinder chamber 57,57a Discharge port 60,60a Laura 61, 62, 61a, 62a Bush 61,61a Low-pressure side bushing member (first bushing member) 62,62a High-pressure side bushing member (second bushing member) 63,63a Vane chamber 70,70a vane 81,81a recess 82,82a Through hole 91,91a Elastic bodies (first elastic body, second elastic body)

Claims

1. It has a cylindrical body (12) and a casing (11) in which lubricating oil is stored, A compression mechanism (50, 50a, 50b, 50c) fixed within the casing (11) for compressing the refrigerant, The casing (11) is located and includes a drive shaft (30) that drives the compression mechanism (50, 50a, 50b, 50c), The compression mechanism (50, 50a, 50b, 50c) is First roller (60,60a), A first vane (70, 70a) formed integrally with the first roller (60, 60a), A pair of first bushes (61, 62, 61a, 62a) slidably support the first vane (70, 70a), A first cylinder (51, 51a) is formed in which a first cylinder chamber (55, 85) in which the first roller (60, 60a) rotates eccentrically and a first vane chamber (63, 63a) in which the first vane (70, 70a) and the first bush (61, 62, 61a, 62a) move, A first plate (52a, 53a, 84) formed on one end side of the first cylinder (51), The first cylinder (51) comprises a second plate (52a, 53a, 84) formed on the other end side, The first bush (61, 62, 61a, 62a) comprises a first bush member (61, 61a) arranged on the suction side and a second bush member (62, 62a) arranged on the discharge side. On the side of the second plate (52a, 53a, 84) facing the first cylinder (51, 51a), The first sliding surface (53b, 84, 84c) that slides against the first roller (60, 60a), A rotary compressor (10) having a first recess (81, 81a) that can accommodate the second bush member (62, 62a) and is recessed from the sliding surface (53b, 84, 84c).

2. In claim 1, The first plate (52a, 53a, 84) is a rotary compressor (10) having discharge ports (57, 57a) for discharging the compressed refrigerant.

3. In claim 1, A rotary compressor (10) further comprising a first elastic body (91) provided in the first recess (81, 81a).

4. In claim 3, The first elastic body (91) is positioned at a distance from the second bushing members (62, 62a) in the rotary compressor (10).

5. In any one of claims 1 to 3, The second plate (52a, 53a, 84) is a rotary compressor (10) having through holes (82, 82a) that connect the first recess (81, 81a) to the lubricating oil storage portion (18) in the casing (11).

6. In claim 5, The drive shaft (30) extends in the vertical direction, The lubricating oil is stored at the bottom of the casing (11). The aforementioned through holes (82, 82a) are connected to a rotary compressor (10) that extends in the vertical direction.

7. In claim 5, The drive shaft (30) extends in the vertical direction, The lubricating oil is stored at the bottom of the casing (11). The through holes (82, 82a) are rotary compressors (10) that extend radially from the drive shaft (30).

8. In claim 1, A rotary compressor (10) in which the depth of the first recess (81, 81a) is 1 / 2 or less of the height of the vane (70, 70a).

9. In claim 1, A rotary compressor (10) in which the depth of the first recess (81, 81a) is 1 / 4 or less of the height of the vane (70, 70a).

10. In claim 1, A rotary compressor (10) in which the depth of the first recess (81, 81a) is 0.5 mm or more and 5 mm or less.

11. In claim 1, Rotary compressor (10), where, viewed from the axial direction of the drive shaft (30), the first recess (81, 81a) has a shape that includes the entire range of movement of the second bush member (62, 62a).

12. In claim 11, Viewed from the axial direction of the drive shaft (30), the first recess (81, 81a) has a portion that overlaps with the first cylinder chamber (55, 85) of the rotary compressor (10).

13. In claim 1, The rotary compressor (10) has, respectively, an arc-shaped first surface (62) formed along the vane chamber (63, 63a) and a second surface (69) facing the cylinder chamber (55, 85).

14. In claim 1 or 3, The compression mechanism (50, 50a, 50b, 50c) is The second roller (60,60a), A second vane (70, 70a) formed integrally with the second roller (60, 60a), A pair of second bushes (61, 62, 61a, 62a) slidably support the second vane (70, 70a), The second cylinder (51, 52a) of the second plate (52a, 53a, 84) is located on the opposite side from the first cylinder (51, 52a), The second cylinder (51, 52a) further comprises a third plate (52a, 53a, 84) positioned on the opposite side from the second plate (52a, 53a, 84), The second cylinder (51, 52a) is formed with a second cylinder chamber (55, 85) in which the second roller (60, 60a) rotates eccentrically, and a second vane chamber (63, 63a) in which the second vane (70, 70a) and the second bush (61, 62, 61a, 62a) move. The second bush (61, 62, 61a, 62a) comprises a third bush member (61, 61a) located on the suction side and a fourth bush member (62, 62a) located on the discharge side. On the side of the second plate (52a, 53a, 84) facing the second cylinder (51, 52a), The second sliding surface (53b, 84, 84c) that slides against the second roller (60, 60a), A rotary compressor (10) having a second recess (81, 81a) that is recessed further than the second sliding surface (53b, 84, 84c) and capable of accommodating the fourth bush member (62, 62a).

15. In claim 14, A rotary compressor (10) further comprising a second elastic body (91a) provided in the second recess (81, 81a).

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