Scroll compressor and refrigerating device

Abstract

A movable-side wrap (72) engages with a fixed-side wrap (62) to form a compression chamber (S). The compression chamber (S) has a first compression chamber (S1) formed by being surrounded by an outer peripheral surface of the movable-side wrap (72) and an inner peripheral surface of the fixed-side wrap (62). A step part (66) is provided at a winding end position of the fixed-side wrap (62). At the time when the first compression chamber (S1) is completely closed, an end of the movable-side wrap (72) at a winding end position comes into contact with the step part (66).

Description

Scroll compressor and refrigeration device

[0001] The present disclosure relates to a scroll compressor and a refrigeration device.

[0002] Patent Document 1 discloses a scroll compressor including a fixed scroll having a fixed-side wrap, and a movable scroll having a movable-side wrap with a different number of turns than the fixed-side wrap and forming a compression chamber by meshing with the fixed-side wrap.

[0003] Japanese Patent Application Laid-Open No. 2016-160816

[0004] By the way, in a general asymmetric scroll compressor, there is a possibility that the closing volume in the suction stroke is less than the maximum volume that can be sucked.

[0005] An object of the present disclosure is to increase the closing volume in the suction stroke by accelerating the closing timing of the compression chamber.

[0006] A first aspect of the present disclosure includes a fixed scroll (60) having a fixed-side wrap (62), and a movable scroll (70) having a movable-side wrap (72) with a different number of turns than the fixed-side wrap (62) and forming a compression chamber (S) by meshing with the fixed-side wrap (62). The compression chamber (S) has a first compression chamber (S1) formed by being surrounded by an outer peripheral surface of the movable-side wrap (72) and an inner peripheral surface of the fixed-side wrap (62). A step portion (66) is provided at the end position of the fixed-side wrap (62). The scroll compressor is such that, at the closing timing of the first compression chamber (S1), an end portion of the winding end position of the movable-side wrap (72) contacts the step portion (66).

[0007] In the first aspect, by the contact between the end portion of the winding end position of the movable-side wrap (72) and the step portion (66), the closing timing of the first compression chamber (S1) can be accelerated and the closing volume in the suction stroke can be increased as compared with the case where the step portion (66) is not provided.

[0008] A second aspect of the present disclosure is a scroll compressor of the first aspect, wherein the stepped portion (66) has a first curved surface (67) to which the end of the end of the winding end position of the movable side wrap (72) slides during a predetermined period of rotation of the movable scroll (70) after the closing timing of the first compression chamber (S1).

[0009] In the second embodiment, the first compression chamber (S1) can be completely closed by the sliding contact between the end of the movable wrap (72) at the winding end position and the first curved surface (67) of the stepped portion (66).

[0010] A third aspect of the present disclosure is a scroll compressor of the second aspect, wherein the radius of curvature r of the first curved surface (67) and the radius of rotation R of the movable scroll (70) satisfy the condition r = R.

[0011] In the third embodiment, the radius of curvature of the first curved surface (67) can be appropriately set.

[0012] A fourth aspect of the present disclosure is a scroll compressor according to the second or third aspect, wherein the radius of curvature r of the first curved surface (67) and the length L of the first curved surface (67) satisfy the condition L ≤ πr / 2.

[0013] In the fourth embodiment, the length of the first curved surface (67) can be appropriately set.

[0014] A fifth aspect of the present disclosure is a scroll compressor of the fourth aspect, wherein the end of the movable side wrap (72) at the winding end position has a projection (75) that protrudes in the winding end direction from a virtual straight line (83) connecting a first end point (81) on the winding end side on the inner circumferential surface of the movable side wrap (72) and a second end point (82) on the winding end side on the outer circumferential surface of the movable side wrap (72), and the winding end position of the fixed side wrap (62) A first reference point (91) is the boundary position between the surface and the stepped portion (66), a second reference point (92) is the point where the rotational trajectory (86) of an arbitrary point (85) on the protruding surface of the protruding portion (75) intersects with a virtual curved surface (96) extending along the first curved surface (67), and L1 is defined as the minimum length at which the length between the first reference point (91) and the second reference point (92) is smallest, and the length L of the first curved surface (67) satisfies the condition L ≤ L1.

[0015] In the fifth embodiment, the length of the first curved surface (67) can be appropriately set so that the protruding portion (75) does not interfere with the stepped portion (66) while the movable side wrap (72) is rotating.

[0016] A sixth aspect of this disclosure is a scroll compressor of the fourth aspect that satisfies the condition L ≤ πr / 4.

[0017] In the sixth embodiment, the length of the first curved surface (67) can be appropriately set.

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

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

[0020] 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 scroll compressor. Figure 3 is a plan cross-sectional view showing the configuration of the fixed scroll and the movable scroll. Figure 4 is a diagram illustrating the positional relationship between the end of the winding end position of the movable wrap and the stepped portion. Figure 5 is a plan cross-sectional view showing the state in which the end of the winding end position of the movable wrap is in contact with the winding end position of the fixed wrap. Figure 6 is a plan cross-sectional view showing the state in which the second compression chamber is completely closed. Figure 7 is a diagram illustrating the positional relationship between the end of the winding end position of the movable wrap and the stepped portion according to this embodiment 2. Figure 8 is a diagram illustrating the positional relationship between the end of the winding end position of the movable wrap and the stepped portion according to this embodiment 3.

[0021] As shown in Figure 1, the scroll 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) has a scroll 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.

[0022] 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.

[0023] As shown in Figure 2, the scroll compressor (10) comprises a casing (20), a motor (30), and a compression mechanism (40). The casing (20) is formed in a vertically elongated cylindrical shape and is configured as a sealed dome type. The motor (30) and the compression mechanism (40) are housed in the casing (20).

[0024] The motor (30) has a stator (31) and a rotor (32). The stator (31) is fixed to the inner circumferential surface of the casing (20). The rotor (32) is positioned inside the stator (31). The drive shaft (11) passes through the rotor (32). The rotor (32) is fixed to the drive shaft (11).

[0025] An oil reservoir (21) is provided at the bottom of the casing (20). Oil is stored in the oil reservoir (21). A suction pipe (12) is connected to the top of the casing (20). A discharge pipe (13) is connected to the body of the casing (20).

[0026] A housing (50) is fixed to the casing (20). The housing (50) is fixed inside the casing (20), for example, by shrink-fitting. The housing (50) is positioned above the motor (30). A compression mechanism (40) is positioned above the housing (50). The inlet end of the discharge pipe (13) is located between the motor (30) and the housing (50).

[0027] A recess (53) is formed in the housing (50). The recess (53) is formed by a recess in a part of the upper surface of the housing (50). An upper bearing (51) is provided below the recess (53).

[0028] The drive shaft (11) extends vertically along the central axis of the casing (20). The drive shaft (11) has a main shaft portion (14) and an eccentric portion (15).

[0029] The eccentric portion (15) is provided at the upper end of the main shaft portion (14). The lower part of the main shaft portion (14) is rotatably supported by a lower bearing (22). The lower bearing (22) is fixed to the inner circumferential surface of the casing (20). For example, a positive displacement pump (25) is provided on the lower bearing (22). The upper part of the main shaft portion (14) passes through the housing (50) and is rotatably supported by an upper bearing (51) of the housing (50).

[0030] The compression mechanism (40) comprises a fixed scroll (60) and a movable scroll (70). The fixed scroll (60) is fixed to the upper surface of the housing (50). The movable scroll (70) is positioned between the fixed scroll (60) and the housing (50).

[0031] The fixed scroll (60) comprises a fixed end plate (61), a fixed lap (62), and an outer peripheral wall (63). The outer peripheral wall (63) is formed in a substantially cylindrical shape. The outer peripheral wall (63) is erected on the outer edge of the front surface (bottom surface in Figure 2) of the fixed end plate (61).

[0032] The fixed-side wrap (62) is formed in a spiral shape. The fixed-side wrap (62) is erected inside the outer peripheral wall (63) of the fixed-side end plate (61).

[0033] The fixed end plate (61) is located on the outer circumference and is formed continuously with the fixed lap (62). The tip surface of the fixed lap (62) and the tip surface of the outer circumference wall (63) are formed substantially flush. The fixed scroll (60) is fixed to the housing (50).

[0034] The movable scroll (70) has a movable end plate (71), a movable wrap (72), and a boss portion (73). The movable wrap (72) is formed in a spiral shape. The movable wrap (72) is formed on the upper surface of the movable end plate (71). The movable wrap (72) has a different number of turns than the fixed wrap (62) (see Figure 3). The movable wrap (72) engages with the fixed wrap (62).

[0035] The boss portion (73) is formed in the center of the lower surface of the movable end plate (71). The eccentric portion (15) of the drive shaft (11) is inserted into the boss portion (73), and the drive shaft (11) is connected to it.

[0036] The compression mechanism (40) has a compression chamber (S) into which the refrigerant flows. The compression chamber (S) is formed between a fixed scroll (60) and a movable scroll (70). The movable scroll (70) is arranged such that its movable side wrap (72) engages with the fixed side wrap (62) of the fixed scroll (60).

[0037] As shown in Figure 3, the compression chamber (S) has a first compression chamber (S1) and a second compression chamber (S2). The first compression chamber (S1) is formed by being surrounded by the outer circumferential surface of the movable side wrap (72) and the inner circumferential surface of the fixed side wrap (62). The second compression chamber (S2) is formed by being surrounded by the inner circumferential surface of the movable side wrap (72) and the outer circumferential surface of the fixed side wrap (62).

[0038] As shown in Figure 2, an intake port (64) is formed in the outer circumferential wall (63) of the fixed scroll (60). The intake port (64) opens near the end of the winding of the fixed-side wrap (62). The downstream end of the intake tube (12) is connected to the intake port (64).

[0039] A discharge port (65) is formed in the center of the fixed end plate (61) of the fixed scroll (60). The discharge port (65) opens on the upper surface of the fixed end plate (61) of the fixed scroll (60). The high-pressure gaseous refrigerant discharged from the discharge port (65) flows out into the lower space (24) through a passage (not shown) formed in the housing (50).

[0040] An oil supply passage (16) is formed inside the drive shaft (11). The oil supply passage (16) extends vertically from the lower end to the upper end of the drive shaft (11). The lower end of the drive shaft (11) is connected to a pump (25). The lower end of the pump (25) is immersed in an oil reservoir (21). As the drive shaft (11) rotates, the pump (25) draws oil from the oil reservoir (21) and transports it to the oil supply passage (16).

[0041] <Operation> The basic operation of the scroll compressor (10) will be described. In FIG. 2, when the motor (30) is activated, the drive shaft (11) to which the rotor (32) is fixed rotates. The movable scroll (70) makes a swirling motion around the axis of the drive shaft (11).

[0042] When the movable scroll (70) makes a swirling motion, the refrigerant sucked from the suction port (64) is compressed in the compression chamber (S). The high-pressure gas refrigerant compressed in the compression chamber (S) is discharged from the discharge port (65) and flows out into the lower space (24) via a passage (not shown) formed in the housing (50). The high-pressure gas refrigerant in the lower space (24) is discharged to the outside of the casing (20) through the discharge pipe (13).

[0043] <Closing timing of the first compression chamber> By the way, in a general asymmetric scroll compressor, there is a possibility that the closing volume in the suction stroke is less than the maximum volume that can be sucked.

[0044] Therefore, in the present embodiment, the closing timing of the first compression chamber (S1) is advanced to increase the closing volume in the suction stroke.

[0045] Specifically, as shown in FIGS. 3 and 4, a stepped portion (66) is provided at the end position of the fixed-side wrap (62). The stepped portion (66) is where the end of the winding end position of the movable-side wrap (72) contacts at the closing timing of the first compression chamber (S1). The closing timing of the first compression chamber (S1) is the timing when the space communicating with the suction port (64) is sealed to form the first compression chamber (S1).

[0046] The stepped portion (66) has a first curved surface (67). The first curved surface (67) is where the end of the winding end position of the movable-side wrap (72) makes a sliding contact within a predetermined period during which the movable scroll (70) swirls after the closing timing of the first compression chamber (S1). In the example shown in FIG. 4, the second end point (82) on the outer peripheral surface of the movable-side wrap (72) at the winding end side makes a sliding contact with the first curved surface (67).

[0047] Specifically, the radius of curvature r of the first curved surface (67) and the turning radius R of the movable scroll (70) are set so as to satisfy the condition r = R. That is, the center of curvature (O) of the first curved surface (67) coincides with the center of the turning locus of the second end point (82).

[0048] As shown in FIG. 4, an end point on the winding end side of the inner peripheral surface of the movable wrap (72) is defined as a first end point (81), an end point on the winding end side of the outer peripheral surface of the movable wrap (72) is defined as a second end point (82), a straight line connecting the first end point (81) and the second end point (82) is defined as a virtual straight line (83), and a reference point at the boundary position between the winding end position of the fixed wrap (62) and the step portion (66) is defined as a first reference point (91).

[0049] In the example shown in FIG. 4, the end portion of the winding end position of the movable wrap (72) is formed in a linear shape that coincides with the virtual straight line (83). Note that the end portion of the winding end position of the movable wrap (72) may be formed in a concave shape that is recessed more than the virtual straight line (83).

[0050] In the example shown in FIG. 4, the position where the second end point (82) of the movable wrap (72) contacts the step portion (66) is taken as the closing start position, and the length of the first curved surface (67) is considered.

[0051] In the example shown in FIG. 4, let the radius of curvature r of the first curved surface (67) and the length L of the first curved surface (67). The length L of the first curved surface (67) is maximized when the central angle of the center of curvature (O) of the first curved surface (67) is 90°. That is, L = 2πr × 90 / 360 = πr / 2.

[0052] Therefore, in the present embodiment, the length L of the first curved surface (67) is set so as to satisfy the condition L ≤ πr / 2.

[0053] In addition, when the central angle of the center of curvature (O) of the first curved surface (67) is maximized at 45°, L = 2πr × 45 / 360 = πr / 4. Therefore, the length L of the first curved surface (T67) may be set so as to satisfy the condition L ≤ πr / 4.

[0054] In this embodiment, where a stepped portion (66) is provided at the winding end position of the fixed-side wrap (62), the first state is reached when the movable scroll (70) is at the eccentric angle position shown in Figure 3. In the first state, the end of the winding end position of the movable-side wrap (72) and the stepped portion (66) are in contact. In the first state, the first compression chamber (S1) is completely closed.

[0055] The movable scroll (70), which is at the eccentric angle position in Figure 3, rotates further until it reaches the eccentric angle position in Figure 5, for example, resulting in the second state. From the first state to the second state, the end of the movable wrap (72) at the winding end position slides against the first curved surface (67) of the stepped portion (66). In the second state, the end of the movable wrap (72) at the winding end position touches the first reference point (91) (see Figure 4) at the boundary position between the winding end position of the fixed wrap (62) and the stepped portion (66).

[0056] If the stepped portion (66) is not provided, the first compression chamber (S1) will be completely closed in the second state. Therefore, if the stepped portion (66) is not provided, the timing of the complete closing of the first compression chamber (S1) will be delayed.

[0057] In contrast, by providing a stepped portion (66) at the end of the winding of the fixed-side wrap (62), as in this embodiment, the closing timing of the first compression chamber (S1) can be accelerated.

[0058] The movable scroll (70), which is at the eccentric angle position in Figure 5, rotates further until it reaches the eccentric angle position in Figure 6, for example, resulting in the third state. In the third state, the second compression chamber (S2) is completely closed. After the third state, the system switches back to the first state, and then sequentially to the second state and then the third state.

[0059] -Effects of Embodiment 1- According to this embodiment, the end of the end of the movable wrap (72) at the winding end position and the stepped portion (66) are in contact, so that the closing timing of the first compression chamber (S1) can be made earlier and the closing volume in the suction stroke can be increased compared to the case where the stepped portion (66) is not provided.

[0060] Furthermore, if there is a discrepancy between the maximum volume timing and the closing timing, there is a risk that some of the refrigerant drawn in during the intake stroke may flow back towards the intake before the compression stroke begins. However, in this embodiment, by aligning the maximum volume timing and the closing timing, the backflow of refrigerant can be suppressed.

[0061] According to this embodiment, the first compression chamber (S1) can be completely closed by the sliding contact between the end of the movable wrap (72) at the winding end position and the first curved surface (67) of the stepped portion (66).

[0062] According to this embodiment, the radius of curvature of the first curved surface (67) can be appropriately set by satisfying the condition r = R when the radius of curvature r of the first curved surface (67) and the rotation radius R of the movable scroll (70) are both r.

[0063] According to this embodiment, the length of the first curved surface (67) can be appropriately set by satisfying the conditions L ≤ πr / 2 for the radius of curvature r of the first curved surface (67) and the length L of the first curved surface (67).

[0064] According to this embodiment, the length of the first curved surface (67) can be appropriately set by satisfying the condition L ≤ πr / 4.

[0065] According to this embodiment, a refrigeration system (1) equipped with a scroll compressor (10) can be provided.

[0066] <Embodiment 2> Hereinafter, the same reference numerals will be used for parts that are the same as in Embodiment 1, and only the differences will be described.

[0067] As shown in Figure 7, the endpoint on the inner circumferential surface of the movable side wrap (72) that is on the winding end side is defined as the first endpoint (81), the endpoint on the outer circumferential surface of the movable side wrap (72) that is on the winding end side is defined as the second endpoint (82), and the line connecting the first endpoint (81) and the second endpoint (82) is defined as the virtual line (83).

[0068] The end of the movable wrap (72) at the winding end position has a projection (75) that protrudes in the winding end direction from the virtual straight line (83). In the example shown in Figure 7, the projection (75) is formed in an arc shape.

[0069] If a protrusion (75) is provided at the end of the winding of the fixed-side wrap (62), then, as in Embodiment 1, if the length L of the first curved surface (67) is L = πr / 4, there is a risk that the protrusion (75) may interfere with the stepped portion (66) during the rotation of the movable-side wrap (72). Therefore, we investigated the length L of the first curved surface (67) to prevent the protrusion (75) from interfering with the stepped portion (66).

[0070] The first reference point (91) is defined as the reference point at the boundary between the end of the fixed wrap (62) and the stepped portion (66), point (85) is defined as an arbitrary point on the protruding surface of the protruding portion (75), the virtual curved surface (96) is defined as the curved surface extending along the first curved surface (67), the second reference point (92) is defined as the reference point where the rotational trajectory (86) of the arbitrary point (85) intersects with the virtual curved surface (96), and the minimum length L1 is defined as the length at which the distance between the first reference point (91) and the second reference point (92) is smallest.

[0071] In this second embodiment, the length L of the first curved surface (67) is set to satisfy the condition L ≤ L1.

[0072] -Effects of Embodiment 2- According to this embodiment, the length of the first curved surface (67) can be appropriately set so that the protruding portion (75) does not interfere with the stepped portion (66) while the movable side wrap (72) is rotating.

[0073] <Embodiment 3> As shown in Figure 8, the end of the movable wrap (72) at the winding end position has a projection (75) that protrudes in the winding end direction from the virtual straight line (83). In the example shown in Figure 8, the projection (75) is formed in a shape that extends in an arc shape from the first endpoint (81) and then in a straight line toward the second endpoint (82).

[0074] Even with a protruding portion (75) of this shape, the minimum length L1 can be defined as the length at which the distance between the second reference point (92), where the rotational trajectory (86) of an arbitrary point (85) on the protruding surface of the protruding portion (75) intersects with the virtual curved surface (96), and the first reference point (91) is smallest. The length L of the first curved surface (67) can then be set to satisfy the condition L ≤ L1.

[0075] -Effects of Embodiment 3- According to this embodiment, the length of the first curved surface (67) can be appropriately set so that the protruding portion (75) does not interfere with the stepped portion (66) while the movable side wrap (72) is rotating.

[0076] 《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.

[0077] As described above, this disclosure is useful for scroll compressors and refrigeration systems.

[0078] 1 Refrigeration device 10 Scroll compressor 60 Fixed scroll 62 Fixed side wrap 66 Stepped section 67 First curved surface 70 Movable scroll 72 Movable side wrap 75 Protrusion 81 First endpoint 82 Second endpoint 83 Virtual straight line 85 Arbitrary point 86 Swivel trajectory 91 First reference point 92 Second reference point 96 Virtual curved surface S Compression chamber S1 First compression chamber

Claims

1. A scroll compressor comprising: a fixed scroll (60) having a fixed-side wrap (62); and a movable scroll (70) having a movable-side wrap (72) with a different number of turns than the fixed-side wrap (62) and which engages with the fixed-side wrap (62) to form a compression chamber (S), wherein the compression chamber (S) has a first compression chamber (S1) formed by being surrounded by the outer circumferential surface of the movable-side wrap (72) and the inner circumferential surface of the fixed-side wrap (62); a stepped portion (66) is provided at the winding end position of the fixed-side wrap (62); and at the timing of the complete closing of the first compression chamber (S1), the end of the winding end position of the movable-side wrap (72) is in contact with the stepped portion (66).

2. The scroll compressor according to claim 1, wherein the stepped portion (66) has a first curved surface (67) that the end of the end of the winding end position of the movable side wrap (72) slides against during a predetermined period of rotation of the movable scroll (70) after the closing timing of the first compression chamber (S1).

3. A scroll compressor according to claim 2, wherein the radius of curvature r of the first curved surface (67) and the rotation radius R of the movable scroll (70) satisfy the condition r = R.

4. A scroll compressor according to claim 2 or 3, wherein the radius of curvature r of the first curved surface (67) and the length L of the first curved surface (67) satisfy the condition L ≤ πr / 2.

5. In the scroll compressor of claim 4, the end of the end of the movable side wrap (72) at the winding end position has a projection (75) that protrudes in the winding end direction from a virtual straight line (83) connecting a first end point (81) on the winding end side on the inner circumferential surface of the movable side wrap (72) and a second end point (82) on the winding end side on the outer circumferential surface of the movable side wrap (72), a first reference point (91) at the boundary position between the winding end position of the fixed side wrap (62) and the stepped portion (66), a second reference point (92) where the rotational trajectory (86) of an arbitrary point (85) on the projection surface of the projection (75) intersects with a virtual curved surface (96) extending along the first curved surface (67), the minimum length at which the length between the first reference point (91) and the second reference point (92) is smallest is defined as L1, and the length L of the first curved surface (67) is L ≤ L1 A scroll compressor that meets the following conditions.

6. A scroll compressor according to claim 4, wherein L ≤ πr / 4.

7. A refrigeration apparatus comprising any one scroll compressor (10) according to claims 1 to 6.

Images