Compressor and freezing air-conditioner

Abstract

To provide a compressor.SOLUTION: A compressor 100 includes a compression mechanism which has a compression mechanism rotor 5, an electric motor 6 which has an electric motor rotor 6b having an end ring 41a, and a shaft 50 which connects the compression mechanism rotor 5 and the electric motor rotor 6b. The electric motor rotor 6b has an insertion hole 43 through which the shaft 50 is inserted. The shaft 50 is inserted into the insertion hole 43 of the electric motor rotor 6b and is fixed to the electric motor rotor 6b by a pair of fixing portions (30, 21) sandwiching end surfaces 44a, 44b on both sides of the electric motor rotor 6b. At least one of the pair of the fixing portions (for example, 30) extends on one side of the electric motor rotor 6b so as to come into contact with an inner diameter surface (for example, 41c) of the end ring (for example, 41a) of the electric motor rotor 6b, and has a cutout 32 so as to be brought into contact with a portion 44c separating from the insertion hole 43 while avoiding an inner diameter side portion 44d around the insertion hole 43 of the end surface 44a of the electric motor rotor 6b.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a compressor and a refrigeration and air conditioning device.

Background Art

[0002] In a screw compressor, which is a semi-hermetic compressor having a driving electric motor inside, maintenance is carried out to reduce the risk of equipment failure and extend the equipment life. To carry out the above-described maintenance, it is desirable that the screw compressor has a decomposable structure, and in particular, it is desirable that the structure is such that the attachment and detachment of the electric motor rotor to and from the shaft portion of the compression mechanism are easy.

[0003] Hitherto, various structures have been known in relation to the coupling between the electric motor rotor and the shaft portion of the compression mechanism in a screw compressor. For example, International Publication No. 2016 / 136028 (Patent Document 1) discloses a screw compressor in which the electric motor rotor is sandwiched between a step formed on the shaft portion of the male rotor and a flat plate and fixed with bolts. Further, Japanese Patent Translation of PCT International Publication No. 2008-514865 (Patent Document 2) discloses a screw compressor in which the electric motor rotor is sandwiched between the end face of a spacer for preventing the bearing inner ring from protruding and a flat plate and fixed with bolts. In these structures, the electric motor rotor and the shaft portion can be detached by removing the bolts, and the structure is configured to enable maintenance.

[0004] However, in the prior art of Patent Document 1, since it is clamped at the inner diameter portion of the motor rotor, contact surface pressure is generated at the inner diameter portion of the motor rotor, which may push in the inner diameter portion of the motor rotor and deform the motor rotor. Also, in the prior art of Patent Document 2, since the contact area between the motor rotor and the spacer is small, high contact surface pressure is generated on the end face of the motor rotor, which may deform the inner diameter portion of the motor rotor. Therefore, in the prior arts disclosed in these Patent Document 1 and Patent Document 2, due to the deformation of the inner diameter portion of the motor rotor, the gap between the outer diameter of the shaft portion of the male rotor and the inner diameter of the motor rotor may decrease, which may hinder the removal of the motor rotor. Furthermore, due to the deformation of the inner diameter portion of the motor rotor, the inner diameter may be eccentric, which may increase the vibration of the compressor.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present disclosure has been made in view of the above points, and the present disclosure suppresses deformation of the motor rotor in the coupling structure between the compression mechanism rotor and the motor rotor, reduces the possibility that the shaft portion cannot be removed from the motor rotor during maintenance, and reduces the possibility that the vibration of the compressor increases due to maintenance, and aims to provide a compressor and a refrigeration and air conditioning device including the compressor.

Means for Solving the Problems

[0007] In the present disclosure, in order to solve the above problems, a compressor having the following features is provided. This compressor includes a compression mechanism including a compression mechanism rotor, an electric motor including an electric motor rotor having an end ring portion, and a shaft portion that couples the compression mechanism rotor and the electric motor rotor. The electric motor rotor has an insertion hole through which the shaft portion is inserted. The shaft portion is inserted into the insertion hole of the electric motor rotor and is fixed to the electric motor rotor by a pair of fixing portions that sandwich the end faces on both sides of the electric motor rotor. At least one of the pair of fixing portions extends so as to contact the inner diameter surface of the end ring portion of the electric motor rotor on one side of the electric motor rotor, and has a notch portion so as to contact a portion away from the insertion hole while avoiding the inner diameter side portion around the insertion hole of the end face of the electric motor rotor.

[0008] In the present disclosure, furthermore, a refrigerating and air-conditioning apparatus including a compressor having the above configuration is also provided.

Advantages of the Invention

[0009] With the above configuration, in the coupling structure between the compression mechanism rotor and the electric motor rotor, deformation of the electric motor rotor is suppressed, the possibility that the shaft portion cannot be removed from the electric motor rotor during maintenance is reduced, and the possibility that the vibration of the compressor increases due to maintenance is reduced.

[0010] In addition, the problems disclosed in the present application and the means for solving them are clarified by the section of the mode for carrying out the invention and the drawings.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments of the present invention are not limited to the specific embodiments described below. In the drawings, the same reference numerals indicate the same or corresponding parts.

[0013] The present disclosure is directed to a compressor and a refrigeration and air conditioning apparatus including the compressor. The compressor according to an embodiment of the present invention includes a compression mechanism including a compression mechanism rotor, an electric motor including an electric motor rotor having an end ring portion, and a shaft portion coupling the compression mechanism rotor and the electric motor rotor. The electric motor rotor has an insertion hole through which the shaft portion is inserted. The shaft portion is inserted into the insertion hole of the electric motor rotor and is fixed to the electric motor rotor by a pair of fixing portions that sandwich the end faces on both sides of the electric motor rotor. Here, at least one of the pair of fixing portions extends so as to be in contact with the inner diameter surface of the end ring portion of the electric motor rotor on one side of the electric motor rotor, and has a notch portion so as to contact a portion away from the insertion hole while avoiding the inner diameter side portion around the insertion hole of the end face of the electric motor rotor.

[0014] With the above configuration, in the coupling structure between the compressor mechanism rotor and the motor rotor, it becomes possible to suppress deformation particularly around the end face of the insertion hole of the motor rotor. As a result, the possibility that the shaft portion cannot be removed from the insertion hole of the motor rotor is reduced. Also, the possibility that the vibration of the compressor increases due to maintenance is reduced.

[0015] In a preferred embodiment, the one fixing portion is configured as a flange separate from the shaft portion. Further, the shaft portion has a stepped portion whose diameter expands with respect to the portion inserted into the insertion hole. The flange abuts against the stepped portion on the side opposite to the motor rotor, and the area of the contact surface of the flange that contacts the portion of the end face of the motor rotor away from the insertion hole is larger than the area of the end face of the stepped portion of the shaft portion. Considering providing a notch in the end face of the stepped portion of the shaft portion and sandwiching it, in order to suppress deformation of the motor rotor, it is necessary to increase the maximum diameter of the shaft portion. When the maximum diameter of the shaft portion increases, not only the outer diameters of the bearings and peripheral components attached to the shaft portion increase, making it impossible to configure it compactly, but also the cost increases. By configuring it as a separate body as described above, it is possible to appropriately fix the end portion of the motor rotor while maintaining the outer diameter of the shaft portion small, which is advantageous from the viewpoints of the compactness and cost of the compressor. Further, in the above preferred embodiment, the inner diameter of the end ring may be larger than the outer diameter of the shaft portion enlarged at the stepped portion.

[0016] In a preferred embodiment, the notch of one of the pair of fixing portions has a taper (inclination) from the center side to the periphery. With such a configuration, the strength of the fixing portion particularly near the notch is improved, and the reliability of the compressor can be enhanced.

[0017] In a preferred embodiment, the one fixing portion is disposed on the base side where the shaft portion is inserted into the insertion hole. When the base side where the shaft portion is inserted into the insertion hole is deformed, it has a greater impact during removal. Therefore, by preferentially suppressing deformation at such a location, it is possible to efficiently improve the maintainability.

[0018] In a specific embodiment, the other fixing portion of the pair of fixing portions may also have the same configuration as the above-mentioned one fixing portion. More specifically, the other fixing portion of the pair of fixing portions extends on the other side of the motor rotor so as to be in contact with the inner diameter surface of the other end ring portion of the motor rotor, and has a second notch portion so as to contact a portion away from the insertion hole while avoiding the inner diameter side portion around the insertion hole of the other end face of the motor rotor. Thereby, deformation on both sides of the insertion hole of the motor rotor is suppressed, maintainability is improved, and vibration of the compressor due to eccentricity is also suppressed.

[0019] In a preferred embodiment, the other fixing portion of the pair of fixing portions may have a plate shape that contacts the other end face of the motor rotor on the other side of the motor rotor. Since the deformation on the side opposite to the root where the shaft portion is inserted into the insertion hole has relatively little influence on the maintainability, by focusing on the root side where the influence is large, it is possible to implement a countermeasure against deformation with high cost-effectiveness.

[0020] In a specific embodiment, further, the other fixing portion of the pair of fixing portions is fastened to the tip of the shaft portion by fastening means.

[0021] In a preferred embodiment, the compressor is a semi-hermetic compressor. In a more preferred embodiment, the compressor is a screw compressor.

[0022] In a specific embodiment, the motor rotor includes a rotor core in addition to the end ring portion, and the insertion hole penetrates the rotor core. In a specific embodiment, the rotor core is composed of laminated steel plates. In a specific embodiment, the compression mechanism further includes another compression mechanism rotor that meshes with the compression mechanism rotor, and a compression chamber is formed by the meshing tooth surfaces of the two compression mechanism rotors. In a specific embodiment, the compression mechanism rotor may typically be a male rotor that meshes with a female rotor. In a specific embodiment, the motor may further include a motor stator that generates a force for rotating the motor rotor. In a specific embodiment, the shaft portion may be the shaft portion of the compression mechanism rotor.

[0023] According to still another embodiment of the present invention, a refrigeration and air conditioning device including a compressor having the above configuration is provided.

[0024] Hereinafter, with reference to FIGS. 1 to 4, the compressor according to the embodiment of the present invention will be described more specifically by taking the semi-hermetic screw compressor 100 as an example.

[0025] The compressor according to the embodiment of the present invention is characterized by the coupling structure between the compression mechanism rotor of the compression mechanism and the motor rotor of the motor. Hereinafter, the overall structure of the compressor will be described first.

[0026] FIG. 1 is a cross-sectional view of a screw compressor 100 according to an embodiment of the present invention. The screw compressor 100 includes a main casing 1, a motor casing 2, a discharge casing 3, and an oil separation casing 4 having a discharge port 13, which are connected to each other in a sealed relationship.

[0027] The motor casing 2 houses a motor 6. The motor 6 includes a motor stator 6a fixed to the motor casing 2 and a motor rotor 6b rotatably provided within the motor stator 6a. The motor 6 is driven by an electric current supplied via a power supply terminal 20. Further, a refrigerant suction port 7 with a strainer attached is formed in the motor casing 2.

[0028] In the main casing 1, a cylindrical bore 15 and a suction port 8 for introducing gas into the cylindrical bore 15 are formed. In the cylindrical bore 15, a male rotor 5 and a female rotor (not shown) rotatably supported by roller bearings 9, 10, 11 and a ball bearing 12 are housed in mesh with each other. A compression chamber 15 is formed by the main casing 1 and the meshing tooth surfaces of the male rotor 5 and the female rotor. The suction-side shaft portion of the male rotor 5 is rotatably supported by the roller bearings 9, 10 provided in the main casing 1, and the discharge-side shaft portion of the male rotor 5 is rotatably supported by the roller bearing 11 and the ball bearing 12 provided in the discharge casing 3. The female rotor also has a similar configuration to the male rotor, although not shown. More specifically, the suction-side shaft portion of the female rotor is rotatably supported by a roller bearing (not shown) provided in the main casing 1, and the discharge-side shaft portion of the female rotor is rotatably supported by a roller bearing (not shown) and a ball bearing provided in the discharge casing 3. The shaft (axis) portion of the male rotor 5 is directly connected to the motor rotor 6b of the electric motor 6. Typically, the male rotor 5 is directly coupled to the motor rotor 6b of the electric motor 6, and the female rotor (not shown) is rotated in synchronization with the male rotor 5. The male rotor 5 that meshes with the female rotor corresponds to the compressor mechanism rotor according to the embodiment of the present invention, but is not necessarily limited to such a configuration. The compression mechanism is constituted by the male rotor 5 and the female rotor.

[0029] The main casing 1 is also provided with an oil reservoir portion 18. The oil reservoir portion 18 is configured such that oil separated from the refrigerant gas accumulates by an oil separator provided in the oil separation casing 4.

[0030] In the discharge casing 3 that houses the roller bearing 11 and the ball bearing 12, a gas discharge passage 14 is formed that communicates the compression section with the oil separation casing 4 and opens into the oil separation casing 4. The discharge casing 3 is fixed to the main casing 1 by fastening means such as bolts. Further, at one end of the discharge casing 3, a shielding plate 17 that closes the bearing chamber 16 housing the roller bearing 11 and the ball bearing 12 is attached. An oil supply passage is formed in the main casing 1 and the discharge casing 3, and it is configured to communicate the oil sump 18 at the lower part of the main casing 1 with each bearing part.

[0031] Next, the flow of the refrigerant gas and oil will be described.

[0032] The low-temperature and low-pressure refrigerant gas inhaled from the refrigerant suction port 7 provided in the motor casing 2 passes through the gas passage provided between the motor 6 and the motor casing 2 and the gap between the motor stator 6a and the motor rotor 6b, cools the motor 6, and then enters from the suction port 8 formed in the main casing 1 into the compression chamber 15 formed by the meshing tooth surfaces of the male rotor 5 and the female rotor (not shown) and the main casing 1.

[0033] Thereafter, the refrigerant gas is sealed in the compression chamber 15 formed by the meshing tooth surfaces of the male rotor 5 and the female rotor (not shown) and the main casing 1 as the male rotor 5 connected to the motor 6 rotates, and is gradually compressed as the compression chamber shrinks, becoming a high-temperature and high-pressure gas, and is discharged from the discharge casing 3 through the discharge passage 14 into the oil separation casing 4. Among the compression reaction forces acting on the male rotor 5 and the female rotor (not shown) during compression, the radial load is supported by the roller bearings 9, 10, 11, and the thrust load is supported by the ball bearing 12.

[0034] The oil for lubricating and cooling these bearings is supplied by differential pressure from an oil reservoir 18 provided in the high-pressure section at the lower part of the main casing 1, passes through an oil passage communicating with each bearing section, and is discharged into the oil separation casing 4 together with the compressed gas. The oil contained in the compressed refrigerant gas is separated by the oil separation casing 4 incorporating an oil separator and stored in the oil reservoir 18 at the lower part of the main casing 1. After the oil separation, the compressed refrigerant gas is discharged from the refrigerant discharge port 13.

[0035] In the screw compressor 100 as shown in FIG. 1, maintenance is carried out to reduce the risk of equipment failure and extend the equipment life. The screw compressor 100 desirably has a decomposable structure for carrying out the above maintenance. In particular, it has a structure that allows easy attachment and detachment of the motor rotor 6b to and from the shaft portion of the compression mechanism.

[0036] On the other hand, when carrying out maintenance, there is a risk that parts may be deformed due to the load during fastening by fastening means such as bolts. In particular, when the inner diameter portion of the motor rotor 6b is deformed, the gap between the outer diameter of the shaft portion to the compression mechanism and the inner diameter of the motor rotor 6b decreases, which may prevent the detachment of the shaft portion from the motor rotor 6b and the attachment of the motor rotor 6b. Further, the deformation of the inner diameter portion of the motor rotor 6b may cause the inner diameter to be eccentric, which may increase the overall vibration of the screw compressor 100.

[0037] Hereinafter, with reference to FIG. 2, the deformation during the manufacture of the motor rotor 6b will be described. FIG. 2 shows the detailed structure of the motor rotor 6b manufactured by the die-casting method. The motor rotor 6b shown in FIG. 2 is, as an example, a so-called cage-type rotor. FIG. 2(A) is a front view seen from one end face 44a of the motor rotor 6b, and FIG. 2(B) is a side view of the motor rotor 6b.

[0038] As shown in FIG. 2, the die-cast motor rotor 6b is manufactured, for example, by preparing a rotor core 40 made of laminated steel plates provided with slits 42, and pouring a non-ferrous metal (such as aluminum or copper) into the slits 42 provided in the rotor core 40 at high speed and high pressure for molding. By casting the rotor core 40 with the molten non-ferrous metal, bars corresponding to the slits 42 and end ring portions 41a and 41b at both ends are integrally molded. An insertion hole 43 for inserting the shaft portion of the male rotor 5 is provided on the central axis of the motor rotor 6b. After molding, the motor rotor 6b heated with the molten non-ferrous metal is cooled by contacting the outside air. At this time, the rotor end faces 44a and 44b with a large area in contact with the outside air rapidly decrease in temperature and contract. Therefore, due to the difference in the cooling rate, the end faces 44a and 44b may be thermally deformed and warp (bulge) in the axial direction. This warping of the end faces 44a and 44b tends to increase in the axial direction toward the inner diameter side.

[0039] Also, when such a motor rotor 6b is attached to the shaft portion of the male rotor 5, a fixing portion such as a stopper is applied to the end faces 44a and 44b of the motor rotor 6b and fixed with bolts. At this time, when the end faces 44a and 44b deformed in the axial direction of the motor rotor 6b are pushed by the load of the bolts, the end faces deformed in the axial direction may protrude in the inner diameter direction. When the end face of the motor rotor 6b protrudes in the inner diameter direction, the gap between the insertion hole 43 of the motor rotor 6b and the shaft portion inserted therein disappears and they come into contact with each other, which may prevent the removal and attachment of the motor rotor 6b during the maintenance of the compressor. Also, due to the protrusion, the central axis of the insertion hole 43 of the motor rotor 6b may tilt and become eccentric, resulting in a problem of increased vibration and noise during the operation of the compressor.

[0040] Therefore, in the screw compressor 100 according to the embodiment of the present invention, the shaft portion 50 coupled to the male rotor 5 is inserted into the insertion hole 43 of the motor rotor 6b and fixed to the motor rotor 6b by a pair of fixing portions 30, 21 that sandwich the end faces 44a, 44b on both sides of the motor rotor 6b. Hereinafter, a configuration having features to be described with reference to FIGS. 3 and 4 will be adopted. That is, one of the pair of fixing portions, the fixing portion 30, extends on the male rotor 5 side of the motor rotor 6b so as to contact the inner diameter surface 41c of the end ring portion 41a of the motor rotor 6b, and has a notch portion 32 so as to contact a portion 44d away from the insertion hole 43 while avoiding the inner diameter side portion 44d around the insertion hole 43 on the end face 44a of the motor rotor 6b.

[0041] Hereinafter, with reference to FIGS. 3 and 4, the coupling structure between the shaft portion 50 of the male rotor 5 and the motor rotor 6b will be described in more detail.

[0042] FIG. 3 is an enlarged cross-sectional view showing the coupling structure between the shaft portion 50 of the male rotor 5 and the motor rotor 6b in the screw compressor 100 according to the embodiment of the present invention. FIG. 4 is a schematic view showing the configuration of the flange 30 in the screw compressor 100 according to the embodiment of the present invention. FIG. 4(A) is a front view of the flange 30 viewed in the rotational axis direction of the shaft portion 50 from the motor 6 side, and FIG. 4(B) is a side view of the flange 30 viewed from a direction perpendicular to the rotational axis direction of the shaft portion 50. FIG. 4(C) is an exploded perspective view of the vicinity of the flange 30.

[0043] As shown in FIG. 3, the shaft portion 50 of the male rotor 5 includes a portion 51 (referred to as a front portion) inserted into the insertion hole 43 of the motor rotor 6b, a step portion 52 whose diameter expands from the front portion 51, and a portion 53 (referred to as a rear portion) coupled to the male rotor 5 after the diameter expands at the step portion 52.

[0044] Between the end face 44a of the motor rotor 6b and the stepped portion 52 of the shaft portion 50, a flange 30 having an opening 33 through which the shaft portion 50 is inserted at its center is installed. On the other end face 44b of the motor rotor 6b, a flat plate 21 having a bolt hole formed at its center is installed. The flat plate 21 is fastened to the tip of the shaft portion 50 by a bolt 22 which is a fastening means. By fitting the bolt 22 through the hole of the flat plate 21 into the threaded hole 54 of the shaft portion 50, the motor rotor 6b is sandwiched between the bolt 22 and the stepped portion 52 by the flange 30 and the flat plate 21 and fixed to the shaft portion 50. The flange 30 extends so as to contact the inner diameter surface 41c of the end ring portion 41a of the motor rotor 6b. That is, the outer diameter of the flange 30 contacts the inner diameter of the end ring portion 41a of the motor rotor 6b (the outer diameter of the flange 30 is slightly smaller than the inner diameter of the end ring portion 41a to the extent that it can be fitted inside the end ring portion 41a). The flange 30 has a notch 32 so as to contact a portion 44c away from the insertion hole 43 while avoiding the inner diameter side portion 44d around the insertion hole 43 on the end face 44a of the motor rotor 6b.

[0045] A notch 32 is formed in the end face 31 of the flange 30 on the motor rotor 6b side. The flange 30 is configured not to contact the end face 44a of the motor rotor 6b at the inner diameter side portion 44d around the insertion hole 43 but to contact at the peripheral portion 44c away from the insertion hole 43. Also, preferably, as shown in FIG. 4, in the direction perpendicular to the rotation axis of the shaft portion, the area of the end face 31 of the flange 30 having the notch 32 is larger than the area of the end face of the stepped portion 52 of the shaft portion 50. Also, in order to increase the area of the end face 31, the inner diameter of the end ring portion 41a can be made larger than the outer diameter of the rear portion 53 of the shaft portion 50 enlarged at the stepped portion 52.

[0046] According to the screw compressor 100 with the above structure, by providing the flange 30 having the notch 32, it will not contact the inner diameter portion of the motor rotor 6b, so it is possible to avoid applying a contact surface pressure to the inner diameter portion of the motor rotor 6b. As a result, it becomes possible to suppress the deformation of the inner diameter portion of the motor rotor 6b. In particular, since the end face 44a of the motor rotor 6b tends to bulge larger toward the inner diameter side in the radial direction due to thermal deformation during manufacturing, by forming the notch 32 in the flange 30, it is possible to prevent the flange 30 from contacting the bulge of the inner diameter portion of the motor rotor 6b. Further, by increasing the area of the notch-side end face 31 of the flange 30 (compared to the area of the end face of the step portion 52), it is possible to increase the contact area and lower the contact surface pressure, and preferably suppress the deformation of the motor rotor 6b.

[0047] In particular, in the above configuration, the flange 30 spreads so that the outer diameter contacts the inner diameter of the end ring portion 41a, and the area of the notch-side end face 31 of the flange 30 is configured to be larger than the area of the end face of the step portion 52 of the shaft portion 50. Therefore, compared with the case of directly sandwiching using the step portion 52 of the shaft portion 50 without using the flange, the contact surface pressure can be further lowered. Also, when considering providing a notch in the end face of the step portion 52 of the shaft portion 50 and sandwiching, in order to increase the contact area at the step portion 52, for example, the outer diameter of the rear portion 53 of the shaft portion 50 can be increased, but the maximum outer shape of the shaft portion 50 will increase. When the maximum outer shape increases, the outer diameters of the bearings and peripheral components attached to the shaft portion 50 also increase, not only making it impossible to configure compactly, but also increasing the cost.

[0048] Note that the radial width of the notch 32 and the distance escaping from the center of the shaft portion 50 can be 50% or more as a ratio to the distance between the outer diameter of the insertion hole 43 and the inner diameter of the end ring portion 41a.

[0049] In anticipation of the deformation caused by the above load, it is also possible to perform relief machining by slightly increasing the diameter of the insertion hole 43 by a certain length on the male rotor 5 side. However, the manufacturing cost of the motor rotor 6b increases. By using the flange 30, it becomes unnecessary to perform relief machining on the insertion hole 43 of the motor rotor 6b, and even considering the cost of providing the flange 30, the cost can be reduced.

[0050] In the embodiment described above, the flange 30 is preferably configured as a separate body from the shaft portion 50 of the male rotor 5. That is, in the embodiment described above, one of the pair of fixing portions is configured as a flange 30 that is a separate body from the shaft portion 50, and the flange 30 abuts against a stepped portion 52 whose diameter expands with respect to the front portion 51 of the shaft portion 50 inserted into the insertion hole 43 on the side opposite to the motor rotor 6b. In this way, it is preferable that the flange 30 is configured as a separate body from the shaft portion 50. By configuring it as a separate body, it is possible to fix the motor rotor 6b and the shaft portion 50 while maintaining the outer diameter of the shaft portion 50 small, which is advantageous from the viewpoints of the compactness and cost of the compressor. However, it is not necessarily limited to the embodiment in which the flange 30 is configured as a separate body from the shaft portion 50, and it goes without saying that the flange 30 may be integrally formed with the shaft portion 50.

[0051] As described above, by providing the notch portion 32 in the flange 30, it is possible to suppress the deformation of the motor rotor 6b due to the load applied to the flange 30 by avoiding contact between the thermally deformed inner diameter side portion of the end face 44a of the motor rotor 6b and the flange 30. Further, by increasing the contact area between the end face 44a of the motor rotor 6b and the flange 30, the contact surface pressure can be reduced, and further deformation of the inner diameter side portion of the motor rotor 6b can be suppressed. Since the deformation of the inner diameter of the motor rotor 6b can be suppressed, the possibility of the motor rotor 6b becoming impossible to remove or attach is reduced, and the maintainability of the compressor is improved. Furthermore, by suppressing the eccentricity of the inner diameter of the motor rotor 6b, an increase in vibration can be prevented.

[0052] Also, in the above-described embodiment, the flange 30 having the notch 32 is disposed on the base side where the shaft portion 50 is inserted into the insertion hole 43. The base side where the shaft portion 50 is inserted into the insertion hole 43 is more affected when it is deformed during removal. Therefore, by preferentially suppressing the deformation of such a portion, it is possible to efficiently improve the maintainability.

[0053] Hereinafter, with reference to FIGS. 5 and 6, a coupling structure between the shaft portion 50 of the male rotor 5 and the motor rotor 6b according to another embodiment will be described.

[0054] FIG. 5 is an enlarged cross-sectional view showing a coupling structure between the shaft portion 50 of the male rotor 5 and the motor rotor 6b in the screw compressor 100 according to another embodiment of the present invention. FIG. 6 is a schematic view showing the configuration of the flange 30' in the screw compressor 100 according to another embodiment of the present invention. FIG. 6(A) is a front view of the flange 30' as viewed in the rotational axis direction of the shaft portion 50 from the motor 6 side, and FIG. 6(B) is a side view of the flange 30' as viewed from a direction perpendicular to the rotational axis direction of the shaft portion 50.

[0055] The flange 30' shown in FIGS. 5 and 6 has the same configuration as the flange 30 shown in FIGS. 3 and 4, but the notch 32' has a taper 35 from the center side to the periphery, and in this respect, it is different from the flange 30 according to the embodiment shown in FIGS. 3 and 4. The taper 35 is formed from the edge of the opening 33 of the flange 30' to the edge of the end face 31 on the motor rotor 6b side, and the inner diameter of the notch 32' of the flange 30' is configured to widen toward the edge of the end face 31 on the motor rotor 6b side.

[0056] According to another embodiment shown in FIGS. 5 and 6, the notch 32' having a taper (inclination) from the center side to the periphery improves the strength of the flange 30 particularly near the notch 32', and the reliability of the compressor 100 can be enhanced.

[0057] Hereinafter, with reference to FIG. 7, a coupling structure between the shaft portion 50 of the male rotor 5 and the motor rotor 6b according to still another embodiment will be described.

[0058] FIG. 7 is an enlarged cross-sectional view showing a coupling structure between the shaft portion of the male rotor and the motor rotor in the screw compressor 100 according to still another embodiment of the present invention. In the embodiments described above, the flange 30 having the notch portion 32 on the inner diameter side was provided only on the end face 44a on the male rotor 5 side of the motor rotor 6b. And on the other side, the plate-shaped flat plate 21 that abuts against the other end face 44b of the motor rotor 6b was provided. However, in other embodiments, a flange having a notch portion may be provided instead of the flat plate 21 on the opposite side.

[0059] As shown in FIG. 7, the flange 30 is provided between the end face 44a on the male rotor 5 side of the motor rotor 6b and the stepped portion 52 of the shaft portion 50, and the flange 36 is also provided between the end face 44b on the opposite side of the motor rotor 6b and the head of the bolt 22. The flange 36 has a hole portion through which the threaded portion of the bolt 22 is inserted at its center. By fitting the bolt 22 through the hole portion of the flange 36 into the threaded hole 54 of the shaft portion 50, the motor rotor 6b is sandwiched between the bolt 22 and the stepped portion 52 by the flanges 30 and 36 and fixed to the shaft portion 50.

[0060] The flange 30 has a notch structure similar to that of the embodiment shown in FIGS. 3 and 4. The flange 36 is also the same, and it extends so as to contact the inner diameter surface 41d of the other end ring portion 41b of the motor rotor 6b. The outer diameter of the flange 36 contacts the inner diameter of the end ring portion 41b of the motor rotor 6b (the outer diameter of the flange 36 is slightly smaller than the inner diameter of the end ring portion 41b to the extent that it can be fitted inside the end ring portion 41b). The flange 36 has a notch portion so as to contact a portion 44e away from the insertion hole 43, avoiding the inner diameter side portion 44f around the insertion hole 43 on the end face 44b of the motor rotor 6b. The flange 36 is configured not to contact the end face 44b of the motor rotor 6b at the inner diameter side portion 44f around the insertion hole 43, but to contact at a portion 44e away from the insertion hole 43.

[0061] As described above, by providing a notch portion in the flange 36, a structure is formed to avoid contact between the flange 36 and the thermally deformed inner diameter side portion of the other end face 44b of the motor rotor 6b, and deformation of the motor rotor 6b due to the load applied to the flange 36 can be suppressed. Since deformation of the inner diameter of the motor rotor 6b can be further suppressed, the possibility of the motor rotor 6b becoming impossible to remove is reduced, and the maintainability of the compressor is improved. Furthermore, by suppressing eccentricity of the inner diameter of the motor rotor 6b, an increase in vibration can be prevented. In FIG. 7, an embodiment is shown in which both side fixing portions are configured by flanges having notch portions. However, any one of the pair of fixing portions may be configured by a flange having a notch portion.

[0062] In the above description, the compressor according to the embodiment of the present invention has been described by taking a semi-hermetic screw compressor as an example. However, the connection structure between the compressor rotor of the compression mechanism and the motor rotor of the motor according to the present invention is not limited to compressors other than semi-hermetic screw compressors, and does not prevent application to other types or other methods of compressors such as hermetic and open types. In particular, it is preferably applicable to those equipped with a driving motor 6 and using a die-cast motor rotor.

[0063] Also, in the embodiments described above, the compressor was not particularly mentioned in terms of its use or the like. However, the compressor according to the embodiments of the present invention can be used as a compressor for any application. In a specific embodiment, the configuration of the present invention may be applied to refrigeration and air-conditioning equipment. Here, refrigeration and air-conditioning equipment generally refers to equipment that utilizes a refrigerant and a refrigeration cycle, such as air conditioners, refrigerators, and freezers. More specifically, examples of refrigeration and air-conditioning equipment include the above-mentioned air conditioners such as package air conditioners and multi-air conditioners for buildings, heat source equipment such as refrigerators and chilling units, commercial refrigerators such as showcases and refrigerated freezers, unit coolers, ice makers, refrigeration equipment for transportation such as car air conditioners, and heat pump water heaters.

[0064] As described above, according to the embodiments of the present invention, in the coupling structure between the compressor mechanism rotor and the motor rotor, deformation of the motor rotor is suppressed, the possibility that the shaft portion cannot be removed from the motor rotor during maintenance is reduced, and the possibility that an increase in vibration occurs due to maintenance is reduced.

[0065] Note that the embodiments of the present invention are not limited to the above-described embodiments, and various modifications may be included. For example, the above-described embodiments have been described in detail for easy understanding, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, for a part of the configuration of each embodiment, addition, deletion, or replacement with other configurations is possible.

Description of Reference Numerals

[0066] 1... Main casing, 2... Motor casing, 3... Discharge casing, 4... Oil separation casing, 5... Male rotor, 6... Electric motor, 6a... Electric motor stator, 6b... Electric motor rotor, 7... Refrigerant suction port, 8... Suction port, 9, 10, 11... Roller bearings, 12... Ball bearing, 13... Refrigerant discharge port, 14... Refrigerant gas discharge passage, 15... Compression chamber, 16... Bearing chamber, 17... Shielding plate, 18... Oil reservoir, 20... Power supply terminal, 21... Flat plate, 22... Bolt, 30... Flange, 31... End face, 32... Notch, 33... Opening, 34... End face, 35... Taper, 36... Flange, 40... Rotor core, 41a, 41b... End ring part, 41c, 41d... End ring inner diameter surface, 42... Slit, 43... Insertion hole, 44a, 44b... End face, 44c, 44e... End face (outer shape side part), 44d, 44f... (End face (inner diameter side part)), 50... Shaft part, 51... Front part, 52... Step part, 53... Rear part, 100... Screw compressor

Claims

1. A compression mechanism including a compressor rotor, an electric motor including an electric motor rotor having an end ring portion, a shaft portion coupling the compressor rotor and the electric motor rotor, and the electric motor rotor has an insertion hole through which the shaft portion is inserted, the shaft portion is inserted into the insertion hole of the electric motor rotor and is fixed to the electric motor rotor by a pair of fixing portions that sandwich both end faces of the electric motor rotor, at least one of the pair of fixing portions extends so as to contact the inner diameter surface of the end ring portion of the electric motor rotor on one side of the electric motor rotor, and has a notch portion that contacts a portion away from the insertion hole while avoiding an inner diameter side portion around the insertion hole of the end face of the electric motor rotor. A compressor.

2. The one fixing portion is configured as a flange separate from the shaft portion. The shaft portion has a stepped portion with an enlarged diameter with respect to a portion inserted into the insertion hole. The flange contacts the stepped portion on the side opposite to the electric motor rotor, and the area of the contact surface of the flange that contacts the portion away from the insertion hole of the end face of the electric motor rotor is larger than the area of the end face of the stepped portion of the shaft portion. The compressor according to claim 1.

3. The notch portion of the one fixing portion of the pair of fixing portions has a taper from the center side to the periphery. The compressor according to claim 1.

4. The one fixing portion is disposed on the root side where the shaft portion is inserted into the insertion hole. The compressor according to claim 1.

5. The other fixing part of the pair of fixing parts is on the other side of the motor rotor, extends so as to be in contact with the inner diameter surface of the other end ring part of the motor rotor, and has a second notch part so as to be in contact with a part away from the insertion hole while avoiding the inner diameter side part around the insertion hole of the other end face of the motor rotor. The compressor according to claim 4.

6. The other fixing part of the pair of fixing parts is on the other side of the motor rotor and has a plate shape that abuts against the other end face of the motor rotor. The compressor according to claim 4.

7. The other fixing part of the pair of fixing parts is fastened to the tip of the shaft part by fastening means. The compressor according to claim 5 or 6.

8. The compressor is a semi-hermetic compressor. The compressor according to claim 1.

9. The compressor is a screw compressor. The compressor according to claim 8.

10. The compressor according to claim 1 Comprising a refrigeration and air conditioning equipment.

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