Refrigerant compressor, refrigeration device, and air-conditioning system

Abstract

A refrigerant compressor (10) uses carbon dioxide as a refrigerant. A crankshaft (25), a motor (21), and a compression mechanism (30) are accommodated in a casing (13). A lower end portion of the crankshaft (25) is provided with an oil supply mechanism (38) having a suction port (39) for sucking up oil stored in a lower end portion of the casing (13). A displacement volume Vcc [cc] per rotation of the compression mechanism (30) and a distance L1 [mm] between the suction port (39) and a lower end of a member joined to the casing (13) among members constituting the compression mechanism (30) satisfy the condition L1 / Vcc > 13.

Description

Refrigerant Compressor, Refrigeration Device, and Air Conditioning System

[0001] The present disclosure relates to a refrigerant compressor, a refrigeration device, and an air conditioning system.

[0002] In Patent Document 1, in a rotary compressor, when there are spaces with different pressures, such as a primary space and a secondary space, inside the casing, pressure fluctuations due to space resonance occur, and the crankshaft moves in the axial direction, causing the crankshaft to collide with the head and generating abnormal noise.

[0003] In the rotary compressor of Patent Document 1, the dimensions of each component are designed or the operation is adjusted so that the operating frequency is (resonance frequency / 1.2) or less, thereby suppressing the generation of abnormal noise associated with the vertical vibration of the crankshaft.

[0004] Japanese Patent Laid-Open No. 10-089252

[0005] The inventors of the present application have found that when carbon dioxide is used as the refrigerant, the mass of the discharged refrigerant becomes larger than that of other refrigerants, so the excitation force that excites pressure fluctuations becomes larger, and abnormal noise associated with the vertical vibration of the crankshaft is likely to occur.

[0006] An object of the present disclosure is to suppress the collision of the crankshaft with the head and reduce abnormal noise when carbon dioxide is used as the refrigerant.

[0007] A first aspect of the present disclosure is a refrigerant compressor using carbon dioxide as a refrigerant, comprising: a crankshaft (25) extending along a first direction and having an eccentric portion (27); a motor (21) for rotating the crankshaft (25); a compression mechanism (30) connected to and driven by the crankshaft (25); and a casing (13) housing the crankshaft (25), the motor (21), and the compression mechanism (30), having a primary space (11) below the motor (21) and a secondary space (12) above the motor (21), wherein the compression mechanism (30) comprises a first head (31) supporting the crankshaft (25) and a cylinder chamber (7) positioned adjacent to the first head (31). The compression mechanism (30) has a cylinder (70) having 1) and a roller (76) fixed to the eccentric portion (27) and rotating eccentrically within the cylinder chamber (71), wherein the upper surface of the eccentric portion (27) overlaps with a part of the lower surface of the first head (31) when viewed from the first direction, and the lower end of the crankshaft (25) is provided with an oil supply mechanism (38) having a suction port (39) that draws up oil stored at the lower end of the casing (13), and the displacement volume Vcc [cc] per revolution of the compression mechanism (30) and the distance L1 [mm] between the lower end of the member of the member constituting the compression mechanism (30) that is joined to the casing (13) and the suction port (39) satisfy the condition L1 / Vcc > 13.

[0008] In the first embodiment, by increasing the distance L1 to satisfy the above-mentioned conditions and bringing the resonance excitation position closer to the node, the pressure fluctuations caused by resonance are reduced, which suppresses the crankshaft (25) from colliding with the first head (31) and reduces abnormal noise.

[0009] A second aspect of the present disclosure is a refrigerant compressor of the first aspect, wherein the compression mechanism (30) is provided with a discharge port (63) for discharging compressed refrigerant into the primary space (11), and the distance L0 [mm] between the upper end of the secondary space (12) and the suction port (39), the distance L [mm] between an intermediate position between the upper end of the secondary space (12) and the suction port (39) and the discharge port (63), and the total weight M [kg] of the rotor (23) of the motor (21) and the crankshaft (25) satisfy the condition Vcc × sin(πL / L0) / M ≤ 0.90.

[0010] In the second embodiment, by satisfying the above-described conditions, pressure fluctuations due to resonance can be reduced, thereby suppressing the generation of abnormal noise when the crankshaft (25) collides with the first head (31).

[0011] Specifically, the smaller the displacement volume Vcc, the smaller the refrigerant discharge rate and the smaller the resonance excitation force. The closer the discharge port (63), which is the resonance excitation position, is to the resonance node, the more difficult it becomes to excite the resonance. The larger the total weight M of the rotor (23) and crankshaft (25), the more difficult it becomes for the crankshaft (25) to move up and down. The larger L1 / Vcc, the smaller Vcc × sin(πL / L0).

[0012] A third aspect of the present disclosure is a refrigerant compressor of the second aspect that satisfies the condition Vcc × sin(πL / L0) / M ≤ 0.86.

[0013] In the third embodiment, the vertical movement of the crankshaft (25) caused by pressure fluctuations due to resonance can be further reduced, thereby suppressing the generation of abnormal noise.

[0014] A fourth aspect of the present disclosure is a refrigerant compressor in any one of the first to third aspects, wherein the cylinder (70) includes a first cylinder (40) having a first cylinder chamber (41) and a second cylinder (50) having a second cylinder chamber (51), and the roller (76) includes a first roller (46) housed in the first cylinder chamber (41) and a second roller (56) housed in the second cylinder chamber (51).

[0015] In the fourth embodiment, the refrigerant compressor includes a first cylinder (40) and a first roller (46), and a second cylinder (50) and a second roller (56). By satisfying the above conditions, even for a multi-cylinder refrigerant compressor with a large volume and prone to generating abnormal noise, pressure fluctuations due to resonance can be reduced and the generation of abnormal noise can be suppressed.

[0016] A fifth aspect of this disclosure is a refrigerant compressor in any one of the first to fourth aspects, wherein the maximum rotational speed of the rotor (23) of the motor (21) is 100 rpm or more.

[0017] In the fifth embodiment, if the maximum rotational speed of the rotor (23) is set to 100 rpm or more, the oil level decreases and the resonance frequency becomes lower, so even if the rotor (23) is rotated at high speed and a collision with resonance occurs, the generation of abnormal noise can be suppressed.

[0018] A sixth aspect of this disclosure is a refrigeration system comprising a refrigerant compressor (10) of any one of the first to fifth aspects.

[0019] In a sixth embodiment, a refrigeration system equipped with a refrigerant compressor (10) can be provided.

[0020] A seventh aspect of this disclosure is an air conditioning system comprising a refrigeration device (1) according to the sixth aspect, wherein the refrigeration device (1) is an air conditioning device that air-conditions a predetermined target space.

[0021] In a seventh embodiment, an air conditioning system can be provided that includes a refrigeration device (1) as an air conditioning device.

[0022] Figure 1 is a refrigerant circuit diagram showing the configuration of the air conditioning system of this embodiment. Figure 2 is a longitudinal cross-sectional view showing the configuration of the refrigerant compressor. Figure 3 is a plan cross-sectional view showing the configuration of the first cylinder and the first roller. Figure 4 is a plan cross-sectional view showing the configuration of the second cylinder and the second roller. Figure 5 is a diagram showing the pressure fluctuation waveform due to spatial resonance. Figure 6 is a graph showing the relationship between the displaced volume Vcc and the distance L1. Figure 7 is a graph showing the relationship between the total weight M and the parameter Vcc × sin(πL / L0). Figure 8 is a graph showing the relationship between the rotor rotation speed and the differential pressure load.

[0023] As shown in Figure 1, the air conditioning system (100) includes a refrigeration device (1) as an air conditioning device for air conditioning a predetermined target space. The refrigeration device (1) has a refrigerant circuit (1a) filled with a refrigerant. In this embodiment, carbon dioxide is used as the refrigerant.

[0024] The refrigerant circuit (1a) includes a refrigerant compressor (10), a heat exchanger (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.

[0025] The refrigeration unit (1) may be a cooling-only unit, a heating-only unit, or an air conditioning unit that switches between cooling and heating. In this case, the refrigeration unit (1) has a switching mechanism (for example, a four-way switching valve) for switching the direction of refrigerant circulation.

[0026] As shown in Figure 2, the refrigerant compressor (10) comprises a casing (13), a drive mechanism (20), and a compression mechanism (30). The drive mechanism (20) and the compression mechanism (30) are housed inside the casing (13).

[0027] The casing (13) is composed of a vertically elongated cylindrical sealed container. An oil reservoir (18) is provided at the bottom of the casing (13). Oil for lubricating the sliding parts of the compression mechanism (30) and the crankshaft (25) is stored in the oil reservoir (18).

[0028] An intake pipe (15) and a discharge pipe (16) are fixed through the body of the casing (13). An accumulator (80) is connected to the intake pipe (15). The accumulator (80) temporarily stores the refrigerant before it is drawn into the refrigerant compressor (10) and separates the liquid refrigerant and oil contained in the gaseous refrigerant into gas and liquid form. The discharge pipe (16) communicates with the secondary space (12) of the casing (13), which will be described later.

[0029] <Drive mechanism> The drive mechanism (20) includes a motor (21) and a crankshaft (25). The motor (21) is positioned above the compression mechanism (30). The motor (21) includes a stator (22) and a rotor (23).

[0030] The stator (22) is fixed to the inner circumferential surface of the casing (13). The rotor (23) extends vertically through the inside of the stator (22). A crankshaft (25) is fixed inside the axis of the rotor (23). When the motor (21) is energized, the crankshaft (25) is rotated together with the rotor (23).

[0031] A primary space (11) and a secondary space (12) are formed inside the casing (13). The primary space (11) is the space below the motor (21). The secondary space (12) is the space above the motor (21).

[0032] The crankshaft (25) is positioned on the axis of the casing (13). The crankshaft (25) extends along a first direction (up and down in Figure 2). An oil supply mechanism (38) is provided at the lower end of the crankshaft (25). The oil supply mechanism (38) has a suction port (39). The oil supply mechanism (38) sucks up the oil stored in the oil reservoir (18) through the suction port (39) and transports it. The transported oil is supplied to the compression mechanism (30) and the sliding parts of the crankshaft (25) through the oil passage (29) inside the crankshaft (25).

[0033] In this embodiment, the crankshaft (25) and the lubrication mechanism (38) are separate components, but the crankshaft (25) and the lubrication mechanism (38) may be integrated.

[0034] The crankshaft (25) has a main shaft portion (26), a first eccentric portion (27), and a second eccentric portion (28). The upper part of the main shaft portion (26) is fixed to the rotor (23) of the motor (21). The first eccentric portion (27) is positioned above the second eccentric portion (28). The axes of the first eccentric portion (27) and the second eccentric portion (28) are eccentric by a predetermined amount from the axis of the main shaft portion (26).

[0035] The portion of the main shaft (26) above the first eccentric portion (27) 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 (28) is rotatably supported by a rear head (33), which will be described later.

[0036] <Compression Mechanism> In the example shown in Figure 2, the compression mechanism (30) is a two-cylinder rotary fluid machine. The compression mechanism (30) is located below the motor (21). The compression mechanism (30) is driven by being connected to the crankshaft (25).

[0037] The refrigerant compressor in this embodiment is of a type in which the vanes rotate eccentrically while connected to a specific position on the outer circumference of the roller. It may be a so-called swing type in which the vanes and roller are formed integrally, or it may be a hinge vane type in which the vanes, which are separate from the roller, are rotatably fixed to the end of the roller. The following describes a compression mechanism (30) in which the vanes and roller are formed integrally.

[0038] The compression mechanism (30) comprises a cylinder (70) having a cylinder chamber (71). A roller (76) is housed in the cylinder chamber (71). The cylinder chamber (71) includes a first cylinder chamber (41) and a second cylinder chamber (51). The cylinder (70) includes a first cylinder (40) having the first cylinder chamber (41) and a second cylinder (50) having the second cylinder chamber (51). The roller (76) includes a first roller (46) housed in the first cylinder chamber (41) and a second roller (56) housed in the second cylinder chamber (51).

[0039] The compression mechanism (30) includes a front head (31) as the first head, a first cylinder (40), a middle plate (32), a second cylinder (50), and a rear head (33).

[0040] The front head (31), first cylinder (40), middle plate (32), second cylinder (50), and rear head (33) are stacked on top of each other from top to bottom and fixed together by fastening bolts (35).

[0041] The front head (31) is fixed to the casing (13) via a mounting plate (36). Note that the front head (31) may be joined to the casing (13) without using the mounting plate (36). Also, instead of the front head (31), any one of the first cylinder (40), the second cylinder (50), and the rear head (33) may be joined to the casing (13).

[0042] The front head (31) is laminated on top of the first cylinder (40). The front head (31) is arranged so as to cover the first cylinder chamber (41) of the first cylinder (40) from above.

[0043] The main shaft portion (26) of the crankshaft (25) is inserted through the central portion of the front head (31). The front head (31) pivotally supports the crankshaft (25) rotatably. A first discharge passage (49) (see FIG. 3) penetrating in the axial direction is formed in the front head (31). The upper surface of the first eccentric portion (27) overlaps with a part of the lower surface of the front head (31) when viewed from the first direction (the axial direction of the crankshaft (25)).

[0044] A first muffler (61) and a second muffler (65) are provided on the upper surface of the front head (31). The first muffler (61) covers the first discharge passage (49) (see FIG. 3) so as to partition the first muffler space (62). The second muffler (65) is disposed in the first muffler space (62). The second muffler (65) partitions a second muffler space (66) between itself and the front head (31). The second discharge passage (59) (see FIG. 4) communicates with the second muffler space (66).

[0045] The first muffler (61) has a first discharge port (63). The first discharge port (63) communicates with the first muffler space (62) and the primary space (11). The compressed refrigerant discharged from the first discharge passage (49) is discharged into the primary space (11) through the first discharge port (63).

[0046] The second muffler (65) has a second discharge port (67). The second discharge port (67) communicates with the second muffler space (66) and the first muffler space (62). The compressed refrigerant discharged from the second discharge passage (59) is discharged into the first muffler space (62) through the second discharge port (67).

[0047] The first cylinder (40) is formed of a flat substantially annular member. The first cylinder (40) is disposed adjacent to the front head (31). As shown in FIG. 3, the first cylinder (40) has a first cylinder chamber (41), a first suction passage (42), and a first vane chamber (43).

[0048] The first cylinder chamber (41) is provided at the central portion of the first cylinder (40). The first suction passage (42) extends radially outward from the inner wall surface of the first cylinder chamber (41) of the first cylinder (40). The first suction passage (42) opens to the outer surface of the first cylinder (40). A suction pipe (15) is connected to the inflow end of the first suction passage (42). The outflow end of the first suction passage (42) communicates with the first cylinder chamber (41).

[0049] The first cylinder chamber (41) houses a first roller (46) and a first vane (47). The first roller (46) is formed in an annular shape. The first roller (46) is fixed to the first eccentric portion (27) of the crankshaft (25). Specifically, the first eccentric portion (27) of the crankshaft (25) is fitted inside the first roller (46).

[0050] The first vane (47) extends radially outward from the first roller (46). The first vane (47) is supported by a pair of first bushes (48). The interior of the first cylinder chamber (41) is partitioned into a low-pressure chamber and a high-pressure chamber by the first vane (47).

[0051] As the first roller (46) eccentrically rotates within the first cylinder chamber (41) with the rotational drive of the crankshaft (25), when the volume of the low-pressure chamber gradually increases with the eccentric rotation of the first roller (46), the refrigerant flowing through the suction pipe (15) is sucked from the first suction passage (42) into the low-pressure chamber.

[0052] Next, when the low-pressure chamber is blocked from the first intake passage (42), the blocked space forms a high-pressure chamber. As the volume of the high-pressure chamber gradually decreases, the internal pressure of the high-pressure chamber increases. 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 (13) and passes through the core cut (not shown) of the motor (21), etc. The high-pressure refrigerant that has flowed out into the secondary space (12) above the motor (21) is sent to the refrigerant circuit from the discharge pipe (16).

[0053] The first vane chamber (43) is located radially outward from the first cylinder chamber (41). The first vane chamber (43) penetrates the first cylinder (40) in the thickness direction. The tip of the first vane (47) is housed in the first vane chamber (43). The first vane (47) oscillates within the first vane chamber (43) in accordance with the eccentric rotation of the first roller (46).

[0054] 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.

[0055] As shown in Figure 4, the second cylinder (50) is formed from a flat, roughly annular member. The second cylinder (50) has a second cylinder chamber (51), a second intake passage (52), and a second vane chamber (53).

[0056] 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).

[0057] The second cylinder chamber (51) houses a second roller (56) and a second vane (57). The second roller (56) is formed in an annular shape. The second eccentric portion (28) of the crankshaft (25) is fitted inside the second roller (56). The second vane (57) extends radially outward from the second roller (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).

[0058] The operation of the second roller (56) is essentially the same as that of the first roller (46), so its explanation will be omitted.

[0059] The second vane chamber (53) is located radially outward from the second cylinder chamber (51). The second vane chamber (53) penetrates the second cylinder (50) in the thickness direction. The tip of the second vane (57) is housed in the second vane chamber (53). The second vane (57) oscillates within the second vane chamber (53) in accordance with the eccentric rotation of the second roller (56).

[0060] 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 crankshaft (25) is inserted through the center of the rear head (33). The rear head (33) rotatably supports the crankshaft (25). A second discharge passage (59) (see Figure 4) 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).

[0061] <Regarding the occurrence of abnormal noise> Incidentally, if there are spaces with different pressures, such as a primary space (11) and a secondary space (12), inside the casing (13), pressure fluctuations due to spatial resonance may occur, causing the crankshaft (25) to move axially, which may cause the crankshaft (25) to collide with the front head (31) and generate abnormal noise.

[0062] The inventors of this application have found that when carbon dioxide is used as a refrigerant, the mass of the discharged refrigerant is larger compared to other refrigerants, which increases the excitation force that excites pressure fluctuations, making it easier for abnormal noises to occur due to vertical vibration of the crankshaft (25).

[0063] Therefore, in this embodiment, when carbon dioxide is used as a refrigerant, the crankshaft (25) is prevented from colliding with the front head (31), thereby reducing abnormal noise.

[0064] As shown in Figures 2 and 5, the distance between the upper end of the secondary space (12) and the suction port (39) of the lubrication mechanism (38) is defined as L0 [mm]. The distance between the intermediate position L0 / 2 between the upper end of the secondary space (12) and the suction port (39) of the lubrication mechanism (38) and the first discharge port (63) is defined as L [mm].

[0065] As shown in Figure 2, the distance between the lower end of the component of the compression mechanism (30) that is joined to the casing (13) and the suction port (39) of the lubrication mechanism (38) is L1 [mm]. In the example shown in Figure 2, the component of the compression mechanism (30) that is joined to the casing (13) is the front head (31) joined via a mounting plate (36). The distance between the first discharge port (63) and the lower end of the front head (31) is L2 [mm]. In this case, L0 / 2 = L + L1 + L2.

[0066] Furthermore, the displacement volume per rotation of the compression mechanism (30) is denoted as Vcc [cc]. Here, the displacement volume Vcc is the volume of the compression chamber at the time when the first cylinder (40) is fully closed, that is, when the low-pressure chamber is sealed within the first cylinder chamber (41) and the compression chamber is formed.

[0067] In this embodiment, we consider the case where the Vcc of the first cylinder (40) and the Vcc of the second cylinder (50) are the same volume. However, if, for example, the Vcc of the first cylinder chamber (41) and the Vcc of the second cylinder chamber (51) are different, the following considerations will be made for the cylinder with the larger Vcc.

[0068] In the following explanation, the rotational speed of the rotor (23) that is above a predetermined rotational speed is referred to as the maximum rotational speed. The predetermined rotational speed is 100 rpm or more. The maximum rotational speed of the rotor (23) is 110 rpm or more and 130 rpm, for example, 120 rpm.

[0069] In Figure 2, the first discharge port (63) is the resonance excitation position. In this embodiment, there is a first muffler (61) and a second muffler (65), and since the first muffler (61) is positioned outside the second muffler (65), the first discharge port (63) of the first muffler (61) is the resonance excitation position. If the first muffler (61) and the second muffler (65) are not provided, the first discharge port (63) that becomes the resonance excitation position becomes the first discharge passage (49) of the front head (31).

[0070] Figure 5 shows the pressure fluctuation waveform due to spatial resonance. In this embodiment, the resonance frequency is, for example, 180 Hz. In the example shown in Figure 5, the excitation position of the resonance is shifted by sin(πL / L0) from the position of the resonance node. The closer the first discharge port (63), which is the excitation position of the resonance, is to the resonance node, the more difficult it becomes to excite the resonance.

[0071] Therefore, in this embodiment, the distance L1 is increased to bring the resonance excitation position closer to the node. Furthermore, the parameter L1 / Vcc is set based on the observation that the smaller the displacement volume Vcc, the smaller the refrigerant discharge rate and the smaller the resonance excitation force.

[0072] In the graph of Figure 6, when the horizontal axis is x and the vertical axis is y, in the case of a conventional refrigerant compressor used as a comparative example, the distance L1 is located below the line indicated by y = 11.4x.

[0073] In contrast, in the refrigerant compressor (10) of this embodiment, distance L1 is located above the line indicated by y = 13.2x. In the example of Figure 6, distance L1 is located above the line indicated by y = 13.5x, except when Vcc = 11.0.

[0074] Therefore, in this embodiment, the parameter L1 / Vcc was set to satisfy the following equation (1).

[0075] L1 / Vcc > 13 ... (1) In this way, by increasing the distance L1 so as to satisfy equation (1), the distance L becomes smaller. In other words, the position of the first discharge port (63), which is the excitation position of resonance, can be brought closer to the node. This suppresses the crankshaft (25) from colliding with the front head (31) and reduces abnormal noise.

[0076] Furthermore, the total weight of the rotor (23) and crankshaft (25) is M [kg]. The total weight M includes the weight of parts attached to the rotor (23) and crankshaft (25) that rotate together with the rotor (23) and crankshaft (25). For example, if balance weights, end plates, etc. are attached to the rotor (23), the weight of those parts is included.

[0077] In this embodiment, we focused on the fact that the larger the total weight M, the more difficult it becomes for the crankshaft (25) to move up and down, and set the parameter Vcc × sin(πL / L0) / M accordingly.

[0078] In the graph in Figure 7, when the horizontal axis is x and the vertical axis is y, the parameter Vcc × sin(πL / L0) for the conventional refrigerant compressor, used as a comparative example, is located above the line indicated by y = 1.09x.

[0079] In contrast, in the refrigerant compressor (10) of this embodiment, the parameter Vcc × sin(πL / L0) is located below the line indicated by y = 0.90x.

[0080] Therefore, in this embodiment, the parameter Vcc × sin(πL / L0) / M was set to satisfy equation (2) below.

[0081] Vcc × sin(πL / L0) / M ≤ 0.90 ... (2) In the example in Figure 7, the parameter Vcc × sin(πL / L0) roughly coincides with the line shown by y = 0.86x around M = 2.8, and is located below the line shown by y = 0.86x at all other points.

[0082] Therefore, in this embodiment, the parameter Vcc × sin(πL / L0) / M was further set to satisfy equation (3) below.

[0083] Vcc × sin(πL / L0) / M ≤ 0.86 ... (3) Thus, the larger the total weight M of the rotor (23) and crankshaft (25), the more difficult it becomes for the crankshaft (25) to move up and down. Also, the larger the parameter L1 / Vcc in equation (1) above, the smaller the parameter Vcc × sin(πL / L0).

[0084] Figure 8 is a graph showing the relationship between rotor rotation speed and differential pressure load. The differential pressure load is the value obtained by multiplying the maximum value of the differential pressure between the primary space (11) and the secondary space (12) by the pressure-receiving area of ​​the rotor (23). The smaller the differential pressure load, the less likely it is that abnormal noise will occur due to the crankshaft (25) colliding with the front head (31).

[0085] As shown in Figure 8, the refrigerant compressor (10) of this embodiment, with the parameter Vcc × sin(πL / L0) / M set to 0.90 or 0.86, exhibits a smaller differential pressure load compared to the comparative example refrigerant compressor with the parameter Vcc × sin(πL / L0) / M set to 1.09. Furthermore, the peak value of the differential pressure load in the refrigerant compressor (10) of this embodiment is smaller than the peak value of the comparative example refrigerant compressor.

[0086] Thus, in this embodiment, by reducing the differential pressure load, which is the maximum value of the differential pressure between the primary space (11) and the secondary space (12), it is possible to suppress the generation of abnormal noise when the crankshaft (25) collides with the front head (31).

[0087] - Effects of the Embodiment - According to this embodiment, by increasing the distance L1 so as to satisfy the conditions of equation (1) described above, and bringing the resonance excitation position closer to the node, the pressure fluctuations caused by resonance are reduced, which suppresses the crankshaft (25) from colliding with the first head (31) and reduces abnormal noise.

[0088] According to this embodiment, by satisfying the conditions of equation (2) described above, pressure fluctuations due to resonance can be reduced, and the generation of abnormal noise caused by the crankshaft (25) colliding with the first head (31) can be suppressed.

[0089] Specifically, the smaller the displacement volume Vcc, the smaller the refrigerant discharge rate and the smaller the resonance excitation force. The closer the discharge port (63), which is the resonance excitation position, is to the resonance node, the more difficult it becomes to excite the resonance. The larger the total weight M of the rotor (23) and crankshaft (25), the more difficult it becomes for the crankshaft (25) to move up and down. The larger L1 / Vcc, the smaller Vcc × sin(πL / L0).

[0090] According to this embodiment, the vertical movement of the crankshaft (25) caused by pressure fluctuations due to resonance can be further reduced, thereby suppressing the generation of abnormal noise.

[0091] According to this embodiment, even for a multi-cylinder refrigerant compressor with a large volume and a tendency to generate abnormal noise, which includes a first cylinder (40) and a first roller (46), and a second cylinder (50) and a second roller (56), the above-mentioned conditions can be met to reduce pressure fluctuations due to resonance and suppress the generation of abnormal noise.

[0092] According to this embodiment, if the maximum rotational speed of the rotor (23) is set to 100 rpm or more, the oil level decreases and the resonance frequency becomes lower. Therefore, even if the rotor (23) is rotated at high speed and a collision with resonance occurs, the generation of abnormal noise can be suppressed.

[0093] According to this embodiment, a refrigeration system equipped with a refrigerant compressor (10) can be provided.

[0094] According to this embodiment, an air conditioning system equipped with a refrigeration device (1) as an air conditioning device can be provided.

[0095] 《Other Embodiments》 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. In addition, the descriptions "first," "second," "third," etc. in the specification and claims are used to distinguish the phrases to which these descriptions are attached, and do not limit the number or order of such phrases.

[0096] As described above, this disclosure is useful for refrigerant compressors, refrigeration equipment, and air conditioning systems.

[0097] 1 Refrigeration unit 10 Refrigerant compressor 11 Primary space 12 Secondary space 13 Casing 21 Motor 23 Rotor 25 Crankshaft 27 First eccentric section (eccentric section) 30 Compression mechanism 31 Front head (first head) 38 Lubrication mechanism 39 Inlet 40 First cylinder 41 First cylinder chamber 46 First roller 50 Second cylinder 51 Second cylinder chamber 56 Second roller 63 First discharge port (discharge port) 70 Cylinder 71 Cylinder chamber 76 Roller 100 Air conditioning system

Claims

1. A refrigerant compressor that uses carbon dioxide as a refrigerant, comprising: a crankshaft (25) extending along a first direction and having an eccentric portion (27); a motor (21) that rotates the crankshaft (25); a compression mechanism (30) connected to and driven by the crankshaft (25); and a casing (13) housing the crankshaft (25), the motor (21), and the compression mechanism (30), having a primary space (11) below the motor (21) and a secondary space (12) above the motor (21), wherein the compression mechanism (30) comprises: a first head (31) that pivotally supports the crankshaft (25); a cylinder (70) positioned adjacent to the first head (31) and having a cylinder chamber (71); and a roller (76) fixed to the eccentric portion (27) and rotating eccentrically within the cylinder chamber (71), The upper surface of the eccentric portion (27) overlaps with a part of the lower surface of the first head (31) when viewed from the first direction, and a lubrication mechanism (38) having a suction port (39) for drawing up oil stored at the lower end of the casing (13) is provided at the lower end of the crankshaft (25), and the displacement volume Vcc [cc] per revolution of the compression mechanism (30) and the distance L1 [mm] between the lower end of the member of the compression mechanism (30) that is joined to the casing (13) and the suction port (39) satisfy the condition L1 / Vcc > 13.

2. A refrigerant compressor according to claim 1, wherein the compression mechanism (30) is provided with a discharge port (63) for discharging compressed refrigerant into the primary space (11), and the distance L0 [mm] between the upper end of the secondary space (12) and the suction port (39), the distance L [mm] between the intermediate position between the upper end of the secondary space (12) and the suction port (39) and the discharge port (63), and the total weight M [kg] of the rotor (23) of the motor (21) and the crankshaft (25) satisfy the condition Vcc × sin(πL / L0) / M ≤ 0.

90.

3. A refrigerant compressor according to claim 2, which satisfies the condition Vcc × sin(πL / L0) / M ≤ 0.

86.

4. A refrigerant compressor according to any one of claims 1 to 3, wherein the cylinder (70) includes a first cylinder (40) having a first cylinder chamber (41) and a second cylinder (50) having a second cylinder chamber (51), and the roller (76) includes a first roller (46) housed in the first cylinder chamber (41) and a second roller (56) housed in the second cylinder chamber (51).

5. A refrigerant compressor according to any one of claims 1 to 4, wherein the maximum rotational speed of the rotor (23) of the motor (21) is 100 rpm or more.

6. A refrigeration system comprising any one of claims 1 to 5, the refrigerant compressor (10).

7. An air conditioning system comprising the refrigeration device (1) of claim 6, wherein the refrigeration device (1) is an air conditioning device that air-conditions a predetermined target space.

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