Rotary compressor and refrigeration device

Abstract

When viewed from the axial direction of a drive shaft (25), a position that is situated on an outer peripheral portion of an eccentric part (60) and intersects a first center line (L1) in a first direction is defined as a first position (P1). A position that is situated on the outer peripheral portion of the eccentric part (60) and intersects the first center line (L1) in a second direction is defined as a second position (P2). A prescribed position that is situated on the outer peripheral portion of the eccentric part (60) and located on the downstream side of the first position (P1) in a rotation direction and on the upstream side of the second position (P2) in the rotation direction is defined a third position (P3). With respect to an axial center (C2) of the eccentric part (60), the angle of the first position (P1) is 0°, the angle of the second position (P2) is 180°, and the angle of the third position (P3) is 65°. The surface hardness at the second position (P2) on the outer peripheral portion of the eccentric part (60) is less than the surface hardness at the third position (P3).

Description

Rotary compressor and refrigeration apparatus

[0001] The present disclosure relates to a rotary compressor and a refrigeration apparatus including the same. A rotary compressor is a compressor that compresses gas in a compression chamber formed in a cylinder by eccentrically rotating a roller inside the cylinder. Rotary compressors generally have a vane for partitioning the compression chamber. Rotary compressors include the so-called rolling roller type, in which a vane separate from the roller rotates eccentrically while the vane abuts against the roller, the so-called swing type, in which a vane formed integrally with the roller swings as the roller rotates eccentrically, and the so-called hinge vane type, in which the roller rotates eccentrically with the tip of the vane rotatably fitted in a recess on the outer peripheral surface of the roller.

[0002] Patent Document 1 discloses a refrigerant compressor in which induction hardening is performed on a part of a sliding portion of a drive shaft (crankshaft) that slides against a bearing material, and the matrix of the drive shaft made of spheroidal graphite cast iron is transformed into martensite to improve wear resistance.

[0003] Japanese Patent Laying-Open No. 2008-280934

[0004] Incidentally, during rotational operation of the drive shaft, a large load is applied to the eccentric portion of the drive shaft. Therefore, hardening the eccentric portion increases the surface hardness of the eccentric portion to suppress wear.

[0005] Here, when the eccentric amount of the eccentric portion is large, there occurs a portion where the thickness of the eccentric portion is small between the inner peripheral surface of an axial oil supply passage formed in the drive shaft and the outer peripheral surface of the eccentric portion.

[0006] Therefore, when the entire circumference of the eccentric portion is uniformly heated and hardened, cracks are likely to occur in the portion of the eccentric portion with small thickness, which may result in poor quality.

[0007] An object of the present disclosure is to suppress the occurrence of cracks in a portion of the eccentric portion having a small thickness.

[0008] A first aspect of the present disclosure comprises a compression mechanism (30) and a drive shaft (25) that rotationally drives the compression mechanism (30), wherein the drive shaft (25) has a main shaft portion (26) and an eccentric portion (60) that is eccentric by a predetermined amount from the axis (C1) of the main shaft portion (26), and the drive shaft (25) has an axial lubrication passage (65) extending in the axial direction and a radial lubrication passage (66) extending radially from the axial lubrication passage (65). The direction from the axis (C1) of the main shaft portion (26) toward the axis (C2) of the eccentric portion (60) is defined as the first direction, and the direction opposite to the first direction is defined as the second direction. The straight line passing through the axis (C1) of the main shaft portion (26) and the axis (C2) of the eccentric portion (60) is defined as the first centerline (L1). When viewed from the axial direction of the drive shaft (25), in the first direction, the first centerline (L1) is defined on the outer circumference of the eccentric portion (60). The position where it intersects with the first center line (L1) is defined as the first position (P1), and the position where it intersects with the first center line (L1) on the outer circumference of the eccentric portion (60) in the second direction, as viewed from the axial direction of the drive shaft (25), is defined as the second position (P2), and the position on the outer circumference of the eccentric portion (60) that is downstream of the first position (P1) in the rotational direction and upstream of the second position (P2), as viewed from the axial direction of the drive shaft (25), is defined as the first position (P1) in the rotational direction and upstream of the second position (P2). The rotary compressor is configured such that a fixed position is designated as the third position (P3), and, viewed from the axial direction of the drive shaft (25), the angle of the first position (P1) is 0°, the angle of the second position (P2) is 180°, and the angle of the third position (P3) is 65°, with the surface hardness of the second position (P2) on the outer circumference of the eccentric portion (60) being less than the surface hardness of the third position (P3).

[0009] In the first embodiment, by making the surface hardness of the second position (P2) on the outer circumference of the eccentric portion (60) smaller than the surface hardness of the third position (P3), it is possible to suppress the occurrence of cracks around the second position (P2) compared to when the entire circumference of the eccentric portion (60) is uniformly heated and hardened.

[0010] A second aspect of the present disclosure is a rotary compressor of the first aspect, wherein the radial oil supply passage (66) opens to the outer circumference of the eccentric portion (60) downstream of the second position (P2) in the rotational direction, the center line of the radial oil supply passage (66) is defined as the second center line (L2), and the position where the second center line (L2) intersects with the outer circumference of the eccentric portion (60) when viewed from the axial direction of the drive shaft (25) is defined as the fourth position (P4), and the surface hardness of the fourth position (P4) on the outer circumference of the eccentric portion (60) is smaller than the surface hardness of the third position (P3).

[0011] In the second embodiment, by making the surface hardness of the fourth position (P4) on the outer circumference of the eccentric portion (60) smaller than the surface hardness of the third position (P3), it is possible to suppress the occurrence of cracks around the radial lubrication passage (66) at the fourth position (P4) compared to when the entire circumference of the eccentric portion (60) is uniformly heated and hardened.

[0012] A third aspect of the present disclosure is a rotary compressor of the second aspect, wherein the surface hardness between the second position (P2) and the fourth position (P4) on the outer circumference of the eccentric portion (60) is less than the surface hardness at the third position (P3).

[0013] In the third embodiment, by making the surface hardness between the second position (P2) and the fourth position (P4) on the outer circumference of the eccentric portion (60) smaller than the surface hardness at the third position (P3), it is possible to suppress the occurrence of cracks between the second position (P2) and the fourth position (P4) compared to when the entire circumference of the eccentric portion (60) is uniformly heated and hardened.

[0014] A fourth aspect of the present disclosure is a rotary compressor according to any one of the first to third aspects, wherein the surface hardness of the second position (P2) on the outer circumference of the eccentric portion (60) is 76% or more and less than 98% of the surface hardness of the third position (P3).

[0015] In the fourth embodiment, by appropriately setting the surface hardness of the second position (P2) on the outer circumference of the eccentric portion (60), it is possible to suppress the occurrence of cracks around the second position (P2) compared to when the entire circumference of the eccentric portion (60) is uniformly heated and hardened.

[0016] A fifth aspect of the present disclosure is a rotary compressor according to the second or third aspect, wherein the surface hardness of the fourth position (P4) on the outer circumference of the eccentric portion (60) is 76% or more and less than 98% of the surface hardness of the third position (P3).

[0017] In the fifth embodiment, by appropriately setting the surface hardness of the fourth position (P4) on the outer circumference of the eccentric portion (60), it is possible to suppress the occurrence of cracks around the radial lubrication passage (66) at the fourth position (P4) compared to when the entire circumference of the eccentric portion (60) is uniformly heated and hardened.

[0018] A sixth aspect of the present disclosure is a rotary compressor according to any one of the first to fifth aspects, wherein, at the second position (P2), the thickness of the eccentric portion (60) between the inner surface of the axial lubrication passage (65) and the outer surface of the eccentric portion (60) is 1.5 mm or more and 2.2 mm or less.

[0019] In the sixth embodiment, it is possible to suppress the occurrence of cracks around the second position (P2) where the wall thickness of the eccentric portion (60) is 1.5 mm or more and 2.2 mm or less.

[0020] A seventh aspect of the present disclosure is a rotary compressor of any one of the first to sixth aspects, wherein the eccentric portion (60) includes a first eccentric portion (61) and a second eccentric portion (62) positioned axially apart from the first eccentric portion (61), and the compression mechanism (30) includes a first cylinder (40) having a first cylinder chamber (41), a second cylinder (50) positioned axially apart from the first cylinder (40) and having a second cylinder chamber (51), a first roller (45) attached to the first eccentric portion (61) and rotating eccentrically within the first cylinder chamber (41), and a second roller (55) attached to the second eccentric portion (62) and rotating eccentrically within the second cylinder chamber (51).

[0021] In the seventh embodiment, the invention relates to a two-cylinder rotary compressor having a first cylinder (40) and a second cylinder (50), and makes it possible to suppress the occurrence of cracks around the second position (P2) of the first eccentric portion (61) and the second eccentric portion (62).

[0022] An eighth aspect of the present disclosure is a refrigeration system comprising a rotary compressor (10) of any one of the first to seventh aspects.

[0023] In the eighth aspect, a refrigeration system equipped with a rotary compressor (10) can be provided.

[0024] Figure 1 is a refrigerant circuit diagram showing the configuration of the refrigeration system of this embodiment. Figure 2 is a longitudinal cross-sectional view showing the configuration of the rotary compressor. Figure 3 is a perspective view showing the configuration of the drive shaft. Figure 4 is a plan cross-sectional view showing the configuration of the first cylinder and the first roller. Figure 5 is a plan cross-sectional view showing the configuration of the second cylinder and the second roller. Figure 6 is a plan cross-sectional view showing the configuration of the eccentric part. Figure 7 is a graph showing the relationship between the angle from the top dead center and the ratio of the magnitude of the force applied to the eccentric part. Figure 8 is a graph showing the relationship between the angle from the first position on the outer circumference of the eccentric part and the ratio of the magnitude of the force applied to the eccentric part. Figure 9 is a diagram illustrating the angle at which the force applied to the eccentric part is maximum.

[0025] As shown in Figure 1, the rotary compressor (10) is installed in the refrigeration unit (1). The refrigeration unit (1) has a refrigerant circuit (1a) filled with refrigerant. The refrigerant circuit (1a) includes the rotary compressor (10), a heat sink (3), a pressure reducing mechanism (4), and an evaporator (5). The pressure reducing mechanism (4) is, for example, an expansion valve. The refrigerant circuit (1a) performs a vapor compression type refrigeration cycle.

[0026] The refrigeration system (1) is an air conditioning system. The air conditioning system may be a cooling-only unit, a heating-only unit, or an air conditioning system that switches between cooling and heating. In this case, the air conditioning system has a switching mechanism (e.g., a four-way switching valve) that switches the direction of refrigerant circulation. The refrigeration system (1) may also be a water heater, a chiller unit, a cooling system that cools the air inside a storage area, etc. The cooling system cools the air inside a refrigerator, freezer, container, etc.

[0027] As shown in Figure 2, the rotary compressor (10) comprises a casing (11), a drive mechanism (20), and a compression mechanism (30). The drive mechanism (20) and the compression mechanism (30) are housed inside the casing (11).

[0028] The casing (11) is a vertically elongated cylindrical sealed container. The suction pipe (15) is fixed through the body of the casing (11). The discharge pipe (16) is fixed through the top of the casing (11).

[0029] An accumulator (6) is connected to the suction pipe (15). The accumulator (6) temporarily stores the refrigerant before it is drawn into the rotary compressor (10) and separates the liquid refrigerant and oil contained in the gaseous refrigerant into gas and liquid forms.

[0030] An oil reservoir (18) is provided at the bottom of the casing (11). Oil is stored in the oil reservoir (18) to lubricate the sliding parts of the compression mechanism (30) and the drive shaft (25).

[0031] <Drive mechanism> The drive mechanism (20) includes a motor (21) and a drive shaft (25). The motor (21) is positioned above the compression mechanism (30). The motor (21) includes a stator (22) and a rotor (23).

[0032] The stator (22) is fixed to the inner circumferential surface of the casing (11). The rotor (23) extends vertically through the inside of the stator (22). A drive shaft (25) is fixed inside the axial center of the rotor (23). When the motor (21) is energized, the drive shaft (25) is rotated together with the rotor (23).

[0033] The drive shaft (25) is positioned on the axis of the casing (11). The drive shaft (25) rotationally drives the compression mechanism (30). The drive shaft (25) has an axial lubrication passage (65) and a radial lubrication passage (66). The axial lubrication passage (65) extends in the axial direction. The radial lubrication passage (66) extends radially from the axial lubrication passage (65). Multiple radial lubrication passages (66) are provided. The opening positions of the radial lubrication passages (66) will be described later.

[0034] An oil supply pump (25a) is provided at the lower end of the drive shaft (25). The oil supply pump (25a) transports the oil stored in the oil reservoir (18). The transported oil is supplied to the compression mechanism (30) and the sliding parts of the drive shaft (25) through the axial oil supply passage (65) and the radial oil supply passage (66).

[0035] The drive shaft (25) has a main shaft portion (26) and an eccentric portion (60). The upper part of the main shaft portion (26) is fixed to the rotor (23) of the motor (21). The eccentric portion (60) is eccentric by a predetermined amount from the axis of the main shaft portion (26). The eccentric portion (60) includes a first eccentric portion (61) and a second eccentric portion (62).

[0036] The first eccentric portion (61) and the second eccentric portion (62) are spaced apart in the axial direction. The first eccentric portion (61) is positioned above the second eccentric portion (62). The axis (C2) of the first eccentric portion (61) and the axis (C2) of the second eccentric portion (62) are eccentric by a predetermined amount from the axis (C1) of the main shaft portion (26) (see Figures 4 and 5). The first eccentric portion (61) and the second eccentric portion (62) are eccentric in directions that are 180° different from each other.

[0037] The portion of the main shaft (26) above the first eccentric portion (61) is rotatably supported by a front head (31), which will be described later. The portion of the main shaft (26) below the second eccentric portion (62) is rotatably supported by a rear head (33), which will be described later.

[0038] A gas vent hole (27) is formed on the drive shaft (25) at a position above the front head (31). The gas vent hole (27) discharges gas contained in the oil passing through the axial lubrication passage (65).

[0039] In the example shown in Figure 2, the radial lubrication passage (66) is provided at positions that open above the first eccentric portion (61) in the main shaft portion (26), at a position that opens on the outer circumference of the first eccentric portion (61), at a position that opens on the outer circumference of the second eccentric portion (62), and at a position that opens below the second eccentric portion (62) in the main shaft portion (26).

[0040] As shown in FIG. 3, a notch (63) is provided at a position where the radial oil supply passage (66) opens in the outer peripheral portion of the first eccentric portion (61). The notch (63) extends vertically along the outer peripheral portion of the first eccentric portion (61). Accordingly, the oil supplied to the outer peripheral portion of the first eccentric portion (61) flows above and below the first eccentric portion (61) through the notch (63). In FIG. 3, the flow of oil is indicated by arrow lines.

[0041] Although not shown in the drawings, a notch (63) is also provided at a position where the radial oil supply passage (66) opens in the outer peripheral portion of the second eccentric portion (62).

[0042] <Compression Mechanism> In the example shown in FIG. 2, the compression mechanism (30) is a two-cylinder rotary compressor (10). The compression mechanism (30) is arranged below the motor (21). The compression mechanism (30) includes a front head (31), a first cylinder (40), a middle plate (32), a second cylinder (50), and a rear head (33).

[0043] The front head (31), the first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33) are stacked sequentially from top to bottom and fixed by fastening bolts (35).

[0044] The front head (31) is fixed to the inner peripheral surface of the casing (11). The front head (31) is stacked on the top of the first cylinder (40). The front head (31) is arranged to cover the first cylinder chamber (41) of the first cylinder (40) from above. A main shaft portion (26) of the drive shaft (25) is inserted through the central portion of the front head (31). The front head (31) rotatably supports the drive shaft (25). A first discharge passage (49) (see FIG. 4) penetrating in the axial direction is formed in the front head (31).

[0045] The first cylinder (40) is formed of a flat substantially annular member. As shown in FIG. 4, the first cylinder (40) includes a first cylinder chamber (41), a first suction passage (42), and a first vane accommodating chamber (43).

[0046] The first cylinder chamber (41) is provided in a central portion of the first cylinder (40). The first suction passage (42) extends from an inner wall surface of the first cylinder chamber (41) toward a radially outer side of the first cylinder (40). The first suction passage (42) opens to an outer surface of the first cylinder (40). A suction pipe (15) is connected to an inflow end of the first suction passage (42). An outflow end of the first suction passage (42) communicates with the first cylinder chamber (41).

[0047] A first roller (45) is accommodated in the first cylinder chamber (41). The first roller (45) includes a first roller main body (46) and a first vane (47). The first roller main body (46) is formed in an annular shape. The first roller (45) is attached to a first eccentric portion (61). Specifically, the first eccentric portion (61) is fitted into the first roller main body (46).

[0048] The first vane (47) extends radially outward from the first roller main body (46). The first vane (47) is supported by a pair of first bushes (48). An interior of the first cylinder chamber (41) is partitioned into a low pressure chamber and a high pressure chamber by the first vane (47).

[0049] The first roller (45) eccentrically rotates within the first cylinder chamber (41) as the drive shaft (25) is rotationally driven. When the volume of the low pressure chamber gradually increases along with the eccentric rotation of the first roller (45), refrigerant flowing through the suction pipe (15) is sucked into the low pressure chamber from the first suction passage (42).

[0050] Next, when the low pressure chamber is blocked from the first suction passage (42), the blocked space constitutes the high pressure chamber. When the volume of the high pressure chamber gradually decreases, the internal pressure of the high pressure chamber rises. When the internal pressure of the high pressure chamber exceeds a predetermined pressure, the refrigerant in the high pressure chamber flows out of the compression mechanism (30) through the first discharge passage (49). This high-pressure refrigerant flows upward through the internal space of the casing (11) and passes through a core cut (not shown) or the like of the motor (21). The high-pressure refrigerant flowing out above the motor (21) is sent to a refrigerant circuit from the discharge pipe (16).

[0051] The first vane housing chamber (43) is located radially outward from the first cylinder chamber (41). The first vane housing chamber (43) penetrates the first cylinder (40) in the thickness direction. The tip of the first vane (47) is housed in the first vane housing chamber (43). The first vane (47) swings within the first vane housing chamber (43) in accordance with the eccentric rotation of the first roller body (46).

[0052] As shown in Figure 2, the middle plate (32) is sandwiched between the first cylinder (40) and the second cylinder (50). The middle plate (32) is positioned to cover the first cylinder chamber (41) of the first cylinder (40) from below. The middle plate (32) is positioned to cover the second cylinder chamber (51) of the second cylinder (50) from above.

[0053] As shown in Figure 5, the second cylinder (50) is formed from a flat, substantially annular member. The second cylinder chamber (51) is positioned axially apart from the first cylinder (40). The second cylinder (50) includes the second cylinder chamber (51), a second intake passage (52), and a second vane housing chamber (53).

[0054] The second cylinder chamber (51) is located in the center of the second cylinder (50). The second intake passage (52) extends radially outward from the inner wall surface of the second cylinder chamber (51) to the second cylinder (50). The second intake passage (52) opens to the outer surface of the second cylinder (50). An intake pipe (15) is connected to the inlet end of the second intake passage (52). The outlet end of the second intake passage (52) communicates with the second cylinder chamber (51).

[0055] The second cylinder chamber (51) houses the second roller (55). The second roller (55) has a second roller body (56) and a second vane (57). The second roller body (56) is formed in an annular shape. The second roller (55) is attached to the second eccentric portion (62). Specifically, the second eccentric portion (62) of the drive shaft (25) is fitted inside the second roller body (56).

[0056] The second vane (57) extends radially outward from the second roller body (56). The second vane (57) is supported by a pair of second bushes (58). The interior of the second cylinder chamber (51) is divided into a low-pressure chamber and a high-pressure chamber by the second vane (57).

[0057] The operation of the second roller (55) is essentially the same as that of the first roller (45), so its explanation will be omitted.

[0058] The second vane housing chamber (53) is located radially outward from the second cylinder chamber (51). The second vane housing chamber (53) penetrates the second cylinder (50) in the thickness direction. The tip of the second vane (57) is housed in the second vane housing chamber (53). The second vane (57) swings within the second vane housing chamber (53) in accordance with the eccentric rotation of the second roller body (56).

[0059] As shown in Figure 2, the rear head (33) is stacked on the lower part of the second cylinder (50). The rear head (33) is positioned to cover the second cylinder chamber (51) of the second cylinder (50) from below. The main shaft portion (26) of the drive shaft (25) is inserted through the center of the rear head (33). The rear head (33) rotatably supports the drive shaft (25). A second discharge passage (59) (see Figure 5) is formed in the rear head (33) that penetrates axially. When the internal pressure of the high-pressure chamber of the second cylinder chamber (51) exceeds a predetermined pressure, the refrigerant in the high-pressure chamber flows out of the compression mechanism (30) through the second discharge passage (59).

[0060] <Regarding the surface hardness of the eccentric part> During the rotational operation of the drive shaft (25), a large load is applied to the eccentric part (60) of the drive shaft (25). Therefore, the surface hardness of the eccentric part (60) is increased by hardening the eccentric part (60) to suppress wear.

[0061] In this case, if the eccentricity of the eccentric portion (60) is large, a portion of the eccentric portion (60) becomes thinner between the inner circumferential surface of the axial lubrication passage (65) formed in the drive shaft (25) and the outer circumferential surface of the eccentric portion (60).

[0062] Therefore, if the entire circumference of the eccentric portion (60) is heated and hardened uniformly, cracks are more likely to occur in the areas of the eccentric portion (60) where the wall thickness is small, which may result in poor quality.

[0063] Therefore, in this embodiment, it is possible to suppress the occurrence of cracks in the thin portion of the eccentric part (60). Since the first eccentric part (61) and the second eccentric part (62) have substantially the same configuration, only the first eccentric part (61) will be described below.

[0064] As shown in Figure 6, the direction from the axis (C1) of the main shaft (26) to the axis (C2) of the eccentric part (60) is defined as the first direction, and the direction opposite to the first direction is defined as the second direction. The straight line passing through the axis (C1) of the main shaft (26) and the axis (C2) of the eccentric part (60) is defined as the first centerline (L1).

[0065] Viewed from the axial direction of the drive shaft (25), the first position (P1) is defined as the position where the first center line (L1) on the outer circumference of the eccentric portion (60) intersects with the first center line (L1) in the first direction.

[0066] Viewed from the axial direction of the drive shaft (25), the second position (P2) is defined as the position where the first center line (L1) intersects with the outer circumference of the eccentric portion (60) in the second direction.

[0067] In this embodiment, the thickness of the eccentric portion (60) between the inner surface of the axial lubrication passage (65) and the outer surface of the eccentric portion (60) at the second position (P2) is 1.5 mm or more and 2.2 mm or less.

[0068] The third position (P3) is defined as a predetermined position on the outer circumference of the eccentric portion (60), viewed from the axial direction of the drive shaft (25), that is downstream of the first position (P1) in the direction of rotation and upstream of the second position (P2) in the direction of rotation. In the example shown in Figure 6, the drive shaft (25) rotates in a clockwise direction.

[0069] Viewed from the axial direction of the drive shaft (25), the angle at the first position (P1) centered on the axis (C2) of the eccentric portion (60) is 0°, the angle at the second position (P2) is 180°, and the angle at the third position (P3) is 65°.

[0070] Furthermore, the center line of the radial lubrication passage (66) is defined as the second center line (L2). The position where the second center line (L2) intersects with the outer circumference of the eccentric portion (60), as viewed from the axial direction of the drive shaft (25), is defined as the fourth position (P4). In this embodiment, the angle of the fourth position (P4) with respect to the axis (C2) of the eccentric portion (60) is 212.6°.

[0071] The surface hardness of the eccentric portion (60) can be increased by high-frequency induction hardening. Alternatively, the eccentric portion (60) may be hardened using a laser.

[0072] The surface hardness at the second position (P2) on the outer circumference of the eccentric portion (60) is less than the surface hardness at the third position (P3). Specifically, the surface hardness at the second position (P2) on the outer circumference of the eccentric portion (60) is 76% or more and less than 98% of the surface hardness at the third position (P3).

[0073] The surface hardness at the fourth position (P4) on the outer circumference of the eccentric portion (60) is less than the surface hardness at the third position (P3). Specifically, the surface hardness at the fourth position (P4) on the outer circumference of the eccentric portion (60) is 76% or more and less than 98% of the surface hardness at the third position (P3).

[0074] The surface hardness between the second position (P2) and the fourth position (P4) on the outer circumference of the eccentric portion (60) is less than the surface hardness at the third position (P3). Specifically, the surface hardness between the second position (P2) and the fourth position (P4) on the outer circumference of the eccentric portion (60) is 76% or more and less than 98% of the surface hardness at the third position (P3).

[0075] Next, the relationship between the rotation angle of the drive shaft (25) and the ratio of the magnitude of the force applied to the outer circumference of the eccentric portion (60) will be explained using Figure 7. As shown in Figure 4, the position in which the eccentric portion (60) of the drive shaft (25) is facing upwards in Figure 4 is defined as top dead center (0°).

[0076] Figure 7 is a graph showing the relationship between the angle from the top dead center and the ratio of the magnitude of the force acting on the eccentric part (60). In Figure 7, the vertical axis represents the ratio of the magnitude of the force acting on the eccentric part (60) when the maximum load acting on the eccentric part (60) is set to 100%.

[0077] In Figure 7, it can be seen that the maximum gas load during rotational drive of the compression mechanism (30) is applied when the drive shaft (25) is rotated 230° from top dead center (0°), and the magnitude of the force acting on the eccentric part (60) is maximum at this position. When the drive shaft (25) is rotated 230° from top dead center (0°), the gas load is applied in the direction indicated by the white-filled arrow in Figure 9.

[0078] Figure 8 is a graph showing the relationship between the angle from the first position (P1) on the outer circumference of the eccentric part (60) and the ratio of the magnitude of the force acting on the eccentric part (60). In Figure 8, the vertical axis represents the ratio of the magnitude of the force acting on the eccentric part (60) when the maximum load acting on the eccentric part (60) is set to 100%.

[0079] As shown in Figure 8, it can be seen that the magnitude of the force acting on the eccentric portion (60) is maximum at a position where the angle from the first position (P1) on the outer circumference of the eccentric portion (60) is 65°.

[0080] Therefore, in this embodiment, high-frequency induction hardening is performed so that the surface hardness is greatest at the third position (P3), which is at an angle of 65° from the first position (P1) on the outer circumference of the eccentric portion (60).

[0081] Here, the direction of the maximum gas load when the compression mechanism (30) is rotated varies depending on the compression conditions, etc. Therefore, it is preferable to increase the surface hardness in a predetermined range including the third position (P3) on the outer circumference of the eccentric portion (60).

[0082] The ratio of the magnitude of the force acting on the second position (P2), which is at an angle of 180° from the first position (P1) on the outer circumference of the eccentric portion (60), is smaller than the ratio of the magnitude of the allowable load shown by the dotted line in Figure 8. Similarly, the ratio of the magnitude of the force acting on the fourth position (P4), which is at an angle of 212.6° from the first position (P1) on the outer circumference of the eccentric portion (60), is smaller than the ratio of the magnitude of the allowable load shown by the dotted line in Figure 8. Therefore, in this embodiment, the surface hardness of the second position (P2) and the surface hardness of the fourth position (P4) are made smaller than the surface hardness of the third position (P3).

[0083] In the following explanation, the specific numerical values ​​of the surface hardness of the outer periphery of the eccentric portion (60) are expressed in Rockwell hardness [HRA].

[0084] The surface hardness of the third position (P3) is, for example, 81 HRA. The surface hardness of the second position (P2) before quenching of the eccentric portion (60) is, for example, 61.5 HRA. Furthermore, the surface hardness of the second position (P2) when no cracks occur, as obtained through experiments, is, for example, 79 HRA.

[0085] Here, the surface hardness of the second position (P2) before hardening of the eccentric portion (60) is calculated as (61.5 / 81) × 100 = 75.9, which is 75.9% of the surface hardness of the third position (P3).

[0086] Furthermore, the surface hardness of the second position (P2) after quenching is calculated as (79 / 81) × 100 = 97.5, which is 97.5% of the surface hardness of the third position (P3). Note that since the eccentric portion (60) is subjected to high-frequency induction hardening, the surface hardness of the fourth position (P4) surrounding the second position (P2), and the surface hardness between the second position (P2) and the fourth position (P4), are the same as the surface hardness of the second position (P2).

[0087] Therefore, in this embodiment, the surface hardness at the second position (P2), the surface hardness at the fourth position (P4), and the surface hardness between the second position (P2) and the fourth position (P4) on the outer circumference of the eccentric portion (60) are set to be 76% or more and less than 98% of the surface hardness at the third position (P3).

[0088] - Effects of the Embodiment - According to this embodiment, by making the surface hardness of the second position (P2) on the outer circumference of the eccentric portion (60) smaller than the surface hardness of the third position (P3), it is possible to suppress the occurrence of cracks around the second position (P2) compared to when the entire circumference of the eccentric portion (60) is uniformly heated and hardened.

[0089] According to this embodiment, by making the surface hardness of the fourth position (P4) on the outer circumference of the eccentric portion (60) smaller than the surface hardness of the third position (P3), it is possible to suppress the occurrence of cracks around the radial lubrication passage (66) at the fourth position (P4) compared to when the entire circumference of the eccentric portion (60) is uniformly heated and hardened.

[0090] According to this embodiment, by making the surface hardness between the second position (P2) and the fourth position (P4) on the outer circumference of the eccentric portion (60) smaller than the surface hardness at the third position (P3), it is possible to suppress the occurrence of cracks between the second position (P2) and the fourth position (P4) compared to when the entire circumference of the eccentric portion (60) is uniformly heated and hardened.

[0091] According to this embodiment, by appropriately setting the surface hardness of the second position (P2) on the outer circumference of the eccentric portion (60), it is possible to suppress the occurrence of cracks around the second position (P2) compared to when the entire circumference of the eccentric portion (60) is uniformly heated and hardened.

[0092] According to this embodiment, by appropriately setting the surface hardness of the fourth position (P4) on the outer circumference of the eccentric portion (60), it is possible to suppress the occurrence of cracks around the radial lubrication passage (66) at the fourth position (P4) compared to when the entire circumference of the eccentric portion (60) is uniformly heated and hardened.

[0093] According to this embodiment, it is possible to suppress the occurrence of cracks around the second position (P2) where the wall thickness of the eccentric portion (60) is 1.5 mm or more and 2.2 mm or less.

[0094] According to this embodiment, the invention relates to a two-cylinder rotary compressor having a first cylinder (40) and a second cylinder (50), and makes it possible to suppress the occurrence of cracks around the second position (P2) of the first eccentric portion (61) and the second eccentric portion (62).

[0095] According to this embodiment, a refrigeration system equipped with a rotary compressor (10) can be provided.

[0096] 《Other Embodiments》 The above embodiment may also have the following configuration.

[0097] In this embodiment, a two-cylinder rotary compressor (10) having a first cylinder (40) and a second cylinder (50) has been described, but a one-cylinder rotary compressor (10) may also be used.

[0098] 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 embodiments, modifications, and other embodiments described above may be combined or substituted as appropriate. In addition, the designations "first," "second," "third," etc. in the specification and claims are used to distinguish the phrases to which these designations are attached, and do not limit the number or order of such phrases.

[0099] As described above, this disclosure is useful for rotary compressors and refrigeration systems.

[0100] 1 Refrigeration unit 10 Rotary compressor 25 Drive shaft 26 Main shaft section 30 Compression mechanism 40 First cylinder 41 First cylinder chamber 45 First roller 50 Second cylinder 51 Second cylinder chamber 55 Second roller 60 Eccentric section 61 First eccentric section 62 Second eccentric section 65 Axial lubrication passage 66 Radial lubrication passage C1 Axis C2 Axis L1 First centerline L2 Second centerline P1 First position P2 Second position P3 Third position P4 Fourth position

Claims

1. The device comprises a compression mechanism (30) and a drive shaft (25) that rotationally drives the compression mechanism (30), wherein the drive shaft (25) has a main shaft portion (26) and an eccentric portion (60) that is eccentric by a predetermined amount from the axis (C1) of the main shaft portion (26), the drive shaft (25) has an axial lubrication passage (65) extending in the axial direction and a radial lubrication passage (66) extending radially from the axial lubrication passage (65), the direction from the axis (C1) of the main shaft portion (26) toward the axis (C2) of the eccentric portion (60) is defined as the first direction, the direction opposite to the first direction is defined as the second direction, and the straight line passing through the axis (C1) of the main shaft portion (26) and the axis (C2) of the eccentric portion (60) is defined as the first centerline (L1). Viewed from the axial direction of the drive shaft (25), the position where the eccentric portion (60) intersects the first center line (L1) in the first direction is defined as the first position (P1), Viewed from the axial direction of the drive shaft (25), the position where the eccentric portion (60) intersects the first center line (L1) in the second direction is defined as the second position (P2), Viewed from the axial direction of the drive shaft (25), a predetermined position on the outer circumference of the eccentric portion (60) that is downstream of the first position (P1) in the rotational direction and upstream of the second position (P2) in the rotational direction is defined as the third position (P3), Viewed from the axial direction of the drive shaft (25), the angle of the first position (P1) with respect to the axis (C2) of the eccentric portion (60) is defined as 0°, the angle of the second position (P2) is defined as 180°, and the angle of the third position (P3) is defined as 65°. A rotary compressor in which the surface hardness at the second position (P2) on the outer circumference of the eccentric portion (60) is smaller than the surface hardness at the third position (P3).

2. A rotary compressor according to claim 1, wherein the radial oil supply passage (66) opens to the outer circumference of the eccentric portion (60) downstream of the second position (P2) in the rotational direction, the center line of the radial oil supply passage (66) is defined as the second center line (L2), the position where the second center line (L2) intersects with the outer circumference of the eccentric portion (60) when viewed from the axial direction of the drive shaft (25) is defined as the fourth position (P4), and the surface hardness of the fourth position (P4) on the outer circumference of the eccentric portion (60) is less than the surface hardness of the third position (P3).

3. A rotary compressor according to claim 2, wherein the surface hardness between the second position (P2) and the fourth position (P4) on the outer circumference of the eccentric portion (60) is less than the surface hardness at the third position (P3).

4. A rotary compressor according to any one of claims 1 to 3, wherein the surface hardness of the second position (P2) on the outer circumference of the eccentric portion (60) is 76% or more and less than 98% of the surface hardness of the third position (P3).

5. A rotary compressor according to claim 2 or 3, wherein the surface hardness of the fourth position (P4) on the outer circumference of the eccentric portion (60) is 76% or more and less than 98% of the surface hardness of the third position (P3).

6. A rotary compressor according to any one of claims 1 to 5, wherein the thickness of the eccentric portion (60) between the inner surface of the axial lubrication passage (65) and the outer surface of the eccentric portion (60) at the second position (P2) is 1.5 mm or more and 2.2 mm or less.

7. A rotary compressor according to any one of claims 1 to 6, wherein the eccentric portion (60) includes a first eccentric portion (61) and a second eccentric portion (62) arranged at an axial distance from the first eccentric portion (61), and the compression mechanism (30) includes a first cylinder (40) having a first cylinder chamber (41), a second cylinder (50) arranged at an axial distance from the first cylinder (40) and having a second cylinder chamber (51), a first roller (45) attached to the first eccentric portion (61) and rotating eccentrically within the first cylinder chamber (41), and a second roller (55) attached to the second eccentric portion (62) and rotating eccentrically within the second cylinder chamber (51).

8. A refrigeration system comprising a rotary compressor (10) according to any one of claims 1 to 7.

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