Compressor, refrigeration / refrigeration device using same, and method for manufacturing compressor

Abstract

The first member (210) and the second member (220) of the compressor are made of an iron-based material, such as iron or an iron alloy. The iron-based material of the first member (210) has a higher carbon content than the iron-based material of the second member (220). The second member (220) is fixed to the first member (210). The second member (220) has a protrusion (211) on its fixing surface, which is formed by laser processing and protrudes from the fixing surface of the first member (210). The first member (210) also has a recess (221) on its fixing surface that fits tightly onto the protrusion (211).

Description

[Technical field]

[0001] The present invention relates to a compressor such as a hermetic refrigerant compressor, a freezing / refrigerating device using the compressor such as a household electric refrigerator-freezer and a showcase, and a method for manufacturing such a compressor. [Background technology]

[0002] In recent years, there has been a demand for compressors such as hermetic refrigerant compressors to be even smaller than before. For example, in the case of household electric refrigerator-freezers, there is a growing demand for larger internal capacity due to the diversification of food ingredients. To achieve this, it is expected that the internal volume will be increased while keeping the external dimensions the same, and one method of increasing the internal volume is to reduce the size of the machine room that houses the hermetic refrigerant compressor. Therefore, in order to reduce the size of the machine room as much as possible, it has been considered to reduce the overall size or height of the hermetic refrigerant compressor.

[0003] An example of a hermetic refrigerant compressor suitable for such miniaturization or low height is an outer rotor type. In an outer rotor type compressor, an electric element is configured such that a rotor rotates on the outside of a stator. For example, Patent Document 1 discloses an example of an outer rotor type compressor.

[0004] The hermetic refrigerant compressor disclosed in Patent Document 1 includes a compression element and an electric element, and as shown in Fig. 10, an electric element 518 includes a stator 520 and a rotor 522. The rotor 522 is arranged rotatably coaxially with the stator 520 so as to surround the periphery of the stator 520.

[0005] Rotor 522 is fixed to crankshaft 508 for driving the compression element, and crankshaft 508 includes main shaft 504 and eccentric shaft 506. Main shaft 504 is journaled by bearing 510. Furthermore, sliding surface 512 is formed on the outer circumferential surface of main shaft 504, and sliding surface 514 is formed on the inner circumferential surface of bearing 510. Therefore, sliding surface 512 and sliding surface 514 form a sliding portion.

[0006] In the stator 520, a coil is wound around a core, and an insulating member 521 is provided to insulate the coil. The stator 520 is fixed to an outer circumferential surface 523 of the bearing 510. In the rotor 522, a permanent magnet 528 is disposed on an outer circumferential end 526 of a disk-shaped frame 524. In addition, a cylindrical rotor shaft hole 530 is formed in the center of the frame 524, and this rotor shaft hole 530 is fixed to the outer circumferential surface of the crankshaft 508. Methods for fixing the rotor shaft hole 530 to the crankshaft 508 include welding and shrink fitting. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] DE102010051266A Summary of the Invention [Problem to be solved by the invention]

[0008] However, when the rotor shaft hole 530 of the rotor 522 is fixed to the crankshaft 508 by, for example, shrink fitting, the insulating member 521 of the stator 520 is easily deformed due to the influence of heat generated during the shrink fitting. This may affect the quality of the electric element 518.

[0009] Furthermore, when the electric element 518 is of the outer rotor type, the rotor 522 has a larger moment of inertia than an inner rotor type rotor. Therefore, the strength (or holding force) for fixing the rotor 522 to the crankshaft 508 needs to be higher than in the case of the inner rotor type. In order to achieve such high strength (holding force) by shrink fitting, it becomes necessary to increase the shrink fit allowance or shrink fit length (area to be shrink fitted).

[0010] If the shrink-fitted area is not sufficient, it is difficult to ensure sufficient strength (holding force) for fixing rotor 522 to crankshaft 508. Furthermore, if the shrink-fitted area is large, the axial length of crankshaft 508 increases, which may cause deformation or the like at the fixing portion of crankshaft 508, affecting the quality, or may make it difficult to miniaturize the hermetic refrigerant compressor. Note that the impact of shrink-fitting on the quality or miniaturization of compressors may occur not only in outer rotor types, but also in inner rotor types.

[0011] The present invention has been made to solve such problems, and aims to make it possible to achieve good quality retention without compromising compactness when fixing components of a compressor, regardless of whether it is an inner rotor type or an outer rotor type. [Means for solving the problem]

[0012] In order to solve the above-mentioned problems, the compressor of the present invention comprises a first member and a second member fixed to the first member, the first member and the second member being composed of an iron-based material which is iron or an iron alloy, the iron-based material constituting the first member having a higher carbon content than the iron-based material constituting the second member, the second member having a fixing surface formed by laser processing and having a convex portion which protrudes relative to a fixed surface of the first member, and the first member having a concave portion on the fixed surface which fits closely into the convex portion.

[0013] According to the above configuration, a convex portion is formed by laser processing on the fixing surface of the second member, and a concave portion is formed on the fixed surface of the first member, and the convex portion fits in a state of being in close contact with the concave portion. Such a convex portion and a concave portion can be easily formed substantially in one step by laser processing, and the state in which the convex portion and the concave portion are in close contact and fitted is sufficiently stable, so that the second member can be well fixed to the first member. According to such a fixing structure, the first member and the second member provided in the compressor can be well fixed without shrink fitting or the like, and the increase in the fixing area can be made smaller than with shrink fitting or the like. Therefore, it is possible to realize good quality retention in the compressor and effectively avoid the risk of hindering miniaturization.

[0014] Furthermore, in order to solve the above-mentioned problems, a manufacturing method for a compressor according to the present invention is configured such that, when fixing a first member and a second member provided in a compressor, the first member is made of an iron-based material which is iron or an iron alloy, and the second member is made of an iron-based material having a lower carbon content than the iron-based material constituting the first member, the fixing surface of the second member is abutted against the fixing surface of the first member, and a laser is irradiated from an outer surface of the second member which is positioned in a normal direction to the fixing surface of the second member or in a direction inclined from the normal direction toward the fixing surface, thereby forming a convex portion on the fixing surface of the second member which protrudes toward the fixed surface of the first member, and a concave portion is formed on the fixed surface of the first member in conjunction with the formation of the convex portion.

[0015] According to the above configuration, by irradiating the second member with a laser from the outer surface located opposite to the fixing surface, a convex portion is formed so as to be driven from the fixing surface, which is the inner surface of the second member, to the fixed surface, which is the outer surface of the first member. Accordingly, a concave portion having a shape corresponding to the convex portion is formed in the fixed surface of the first member. As a result, the fixed surface of the first member is pressed by the fixing surface of the second member, so that the second member can be well fixed to the first member.

[0016] Furthermore, according to the above configuration, a strong fixed state (bonded state) can be achieved simply by forming a partial protrusion by laser irradiation. Therefore, the increase in the fixed area can be reduced compared to shrink fitting, etc. This makes it possible to avoid increasing the size of the compressor and promote miniaturization. Furthermore, compared to shrink fitting, etc., no large, special manufacturing equipment (heating furnace, drying furnace, etc.) is required, so it is also possible to avoid the manufacturing equipment becoming larger or more complicated.

[0017] Furthermore, according to the above configuration, since it is only necessary to locally irradiate the portion to be fixed (joined) with a laser, it is possible to suppress the amount of heat given to the first member and the second member. This makes it possible to effectively suppress the influence of heat on the first member or the second member. Therefore, it is possible to further improve the quality of the portion (fixing portion) where the first member and the second member are fixed.

[0018] Furthermore, the refrigeration / refrigeration device of the present invention may be configured to include a compressor configured as described above, a radiator, a pressure reducing device, and a heat absorber, and to have a refrigerant circuit in which these are connected in a ring shape by piping.

[0019] The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, taken in conjunction with the accompanying drawings. Effect of the Invention

[0020] In the present invention, the above-mentioned configuration has the effect of making it possible to achieve good quality retention without compromising compactness when fixing components of a compressor, regardless of whether it is an inner rotor type or an outer rotor type. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic vertical cross-sectional view showing an example of the configuration of a compressor according to a first embodiment of the present invention. [Diagram 2]2 is a schematic partial cross-sectional view showing an example of the configuration of a fixing portion of a first member and a second member included in the compressor shown in FIG. 1. [Diagram 3] 3 is a comparison diagram of a side view and a cross-sectional view showing an example of a specific configuration of the fixing portion shown in FIG. 2. [Figure 4] FIG. 4 is a diagram showing a laser microscope photograph of a specific example of the fixing portion shown in FIG. 2 or FIG. 3. [Diagram 5] FIG. 6 is a schematic vertical cross-sectional view showing an example of the configuration of a compressor according to a second embodiment of the present invention. [Figure 6] 6 is a schematic partial cross-sectional view showing an example of the configuration of a fixing portion of a first member and a second member included in the compressor shown in FIG. 5. [Figure 7] FIG. 11 is a schematic vertical sectional view showing an example of the configuration of a compressor according to a third embodiment of the present invention. [Figure 8] 8 is a schematic partial cross-sectional view showing an example of the configuration of a fixing portion of a first member and a second member included in the compressor shown in FIG. 7. [Figure 9] FIG. 11 is a schematic diagram showing an example of the configuration of a refrigeration / freezing device according to a fourth embodiment of the present invention. [Figure 10] FIG. 11 is a schematic vertical cross-sectional view showing the configuration of a main part of an electric element and a compression element in a conventional compressor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The compressor according to the present disclosure comprises a first member and a second member fixed to the first member, the first member and the second member being composed of an iron-based material which is iron or an iron alloy, the iron-based material constituting the first member having a higher carbon content than the iron-based material constituting the second member, the second member having a fixing surface formed by laser processing and having a convex portion which protrudes relative to a fixed surface of the first member, and the first member having a concave portion on the fixed surface which fits closely into the convex portion.

[0023] According to the above configuration, a convex portion is formed by laser processing on the fixing surface of the second member, and a concave portion is formed on the fixed surface of the first member, and the convex portion fits in a state of being in close contact with the concave portion. Such a convex portion and a concave portion can be easily formed substantially in one step by laser processing, and the state in which the convex portion and the concave portion are in close contact and fitted is sufficiently stable, so that the second member can be well fixed to the first member. According to such a fixing structure, the first member and the second member provided in the compressor can be well fixed without shrink fitting or the like, and the increase in the fixing area can be made smaller than with shrink fitting or the like. Therefore, it is possible to realize good quality retention in the compressor and effectively avoid the risk of hindering miniaturization.

[0024] In a compressor of the above configuration, when the surface of the second member located opposite the protruding direction of the convex portion is defined as the convex portion opposing surface, the convex portion opposing surface of the second member may be configured to have laser irradiation marks formed at a position opposite the position of the convex portion on the fixing surface, via the second member main body.

[0025] According to the above-mentioned configuration, the convex portion and the laser irradiation mark on the second member are in a positionally opposing relationship, so that by irradiating the outer surface of the second member with a laser, it is possible to easily form a convex portion on the inner surface (fixing surface) of the second member, and also to easily form a concave portion on the fixed surface of the first member.

[0026] Furthermore, the compressor having the above configuration may include an electric element consisting of at least a stator and a rotor, and a compression element driven by the electric element, the compression element having a crankshaft which is an axis portion, the first member being the crankshaft, and the second member being a balance weight fixed to the crankshaft, or a support portion for the rotor fixed to the crankshaft.

[0027] According to the above configuration, the crankshaft of the compressor is often made of cast iron, and the balance weight or rotor support portion fixed to the crankshaft (for example, in an outer rotor type rotor, this can be a rotor shaft hole portion provided in a frame, and in an inner rotor type rotor, this can be a portion of the lower part of the rotor that contacts the outer circumferential surface of the crankshaft) is often made of steel. Cast iron has a higher carbon content than steel. Therefore, by irradiating the outer surface of the balance weight or the rotor support portion with a laser, it is possible to easily form convex portions on the inner surface of these portions and also to easily form concave portions in the crankshaft.

[0028] In the compressor having the above configuration, the rotation speed of the crankshaft may be 60 rps or more.

[0029] According to the above configuration, when the rotation speed of the crankshaft is 60 rps or more, a large centrifugal force acts on the rotor, and if the crankshaft suddenly stops from this high-speed operation, a large torque is likely to be generated on the rotor. In contrast, in the compressor of the above configuration, even when a large centrifugal force acts on the rotor due to high-speed operation, or when a large torque is generated due to the rotor suddenly stopping, the rotor is firmly fixed (held) to the crankshaft, so that it is possible to prevent the rotor from shifting from its fixed position on the crankshaft. Therefore, it is possible to effectively suppress a decrease in the durability of the compressor, and good reliability can be achieved.

[0030] The refrigeration / freezing device according to the present disclosure may have a refrigerant circuit including a compressor, a radiator, a pressure reducing device, and a heat absorber, all of which are connected in a ring shape by piping.

[0031] According to the above configuration, the compressor achieves good quality retention without compromising compactness. Therefore, the reliability of the refrigeration / freezing device can be improved, and the compressor can be made compact, ensuring a large storage space.

[0032] Furthermore, the manufacturing method for a compressor according to the present disclosure may be configured so that, when fixing a first member and a second member provided in a compressor, the first member is made of an iron-based material that is iron or an iron alloy, and the second member is made of an iron-based material having a lower carbon content than the iron-based material constituting the first member, the fixing surface of the second member is abutted against the fixing surface of the first member, and a laser is irradiated from an outer surface of the second member located in a normal direction to the fixing surface of the second member or in a direction inclined from the normal direction toward the fixing surface, thereby forming a convex portion on the fixing surface of the second member that protrudes toward the fixed surface of the first member, and a concave portion is formed on the fixed surface of the first member in conjunction with the formation of the convex portion.

[0033] According to the above configuration, by irradiating the second member with a laser from the outer surface located opposite to the fixing surface, a convex portion is formed so as to be driven from the fixing surface, which is the inner surface of the second member, to the fixed surface, which is the outer surface of the first member. Accordingly, a concave portion having a shape corresponding to the convex portion is formed in the fixed surface of the first member. As a result, the fixed surface of the first member is pressed by the fixing surface of the second member, so that the second member can be well fixed to the first member.

[0034] Furthermore, according to the above configuration, a strong fixed state (bonded state) can be achieved simply by forming a partial protrusion by laser irradiation. Therefore, the increase in the fixed area can be reduced compared to shrink fitting, etc. This makes it possible to avoid increasing the size of the compressor and promote miniaturization. Furthermore, compared to shrink fitting, etc., no large, special manufacturing equipment (heating furnace, drying furnace, etc.) is required, so it is also possible to avoid the manufacturing equipment becoming larger or more complicated.

[0035] Furthermore, according to the above configuration, since it is only necessary to locally irradiate the portion to be fixed (joined) with a laser, it is possible to suppress the amount of heat given to the first member and the second member. This makes it possible to effectively suppress the influence of heat on the first member or the second member. Therefore, it is possible to further improve the quality of the portion (fixing portion) where the first member and the second member are fixed.

[0036] Hereinafter, a representative embodiment of the present invention will be described with reference to the drawings. In the following, the same or corresponding elements are denoted by the same reference numerals throughout the drawings, and duplicated descriptions thereof will be omitted.

[0037] (Embodiment 1) [Compressor configuration] First, a representative configuration example of a hermetic refrigerant compressor according to the first embodiment of the present disclosure will be specifically described with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view showing an example of the configuration of a hermetic refrigerant compressor 100A (hereinafter, may be abbreviated as compressor 100A) according to the first embodiment of the present disclosure.

[0038] 1, compressor 100A has sealed container 102 filled with, for example, R600a as refrigerant gas 181, and mineral oil stored at the bottom as lubricating oil 180. Also, sealed container 102 contains compressor body 108, which is elastically supported by suspension spring 190. Also, compressor body 108 includes electric element 104 and compression element 106.

[0039] The electric element 104 is composed of at least a stator 150 and a rotor 152. The compression element 106 is a reciprocating type structure driven by the electric element 104, and includes a crankshaft 120, a cylinder block 130, a piston 140, a connecting means 142, etc. The crankshaft 120 is composed of at least a main shaft 124 to which the rotor 152 is press-fitted, an eccentric shaft 122 formed eccentrically with respect to the main shaft 124, and a flange 128 connecting the main shaft 124 and the eccentric shaft 122.

[0040] 1, the eccentric shaft 122 of the crankshaft 120 is located above the compressor 100A, and the main shaft 124 is located below the compressor 100A. Therefore, this up-down positional relationship (direction) is used when explaining the position of the crankshaft 120. For example, the upper end of the eccentric shaft 122 faces the inner upper surface of the sealed container 102, and the lower end of the eccentric shaft 122 is connected to the main shaft 124. The upper end of the main shaft 124 is connected to the eccentric shaft 122, the lower end of the main shaft 124 faces the inner lower surface of the sealed container 102, and the lower end of the main shaft 124 is immersed in the lubricating oil 180.

[0041] A balance weight 171 is fixed to the uppermost end of the crankshaft 120, i.e., the upper end of the eccentric shaft 122. The balance weight 171 is provided to reduce the imbalance of the load on the crankshaft 120. An oil supply mechanism 125 is provided below the crankshaft 120, i.e., below the main shaft 124, and supplies lubricating oil 180 from the lower end of the main shaft 124, which is immersed in lubricating oil 180, to the upper end of the eccentric shaft 122.

[0042] The outer peripheral surface of the main shaft 124 of the crankshaft 120 includes a sliding surface 126 and a non-sliding surface 127. In this disclosure, the "sliding surface" refers to the outer peripheral surface or inner peripheral surface of a plurality of sliding members constituting a sliding portion, which is in slidable contact with the inner peripheral surface or outer peripheral surface of the other. The "non-sliding surface" is a surface that is different from the sliding surface and does not contact the inner peripheral surface or outer peripheral surface of the other. In the present embodiment 1, the non-sliding surface 127 is configured such that the outer diameter of the main shaft 124 is smaller than the sliding surface 126 (the outer diameter is narrowed, it is recessed from the sliding surface 126, or it is formed by hollowing out).

[0043] In the first embodiment, cylinder block 130 is made of, for example, cast iron, forms a substantially cylindrical compression chamber 133, and includes bearing 134 that supports main shaft 124 of crankshaft 120. An inner peripheral surface 135 of bearing 134 is in slidable contact with the outer peripheral surface, i.e., the sliding surface, of main shaft 124. Therefore, bearing inner peripheral surface 135 also serves as a sliding surface.

[0044] When the main shaft 124 is supported by the bearing 134, the non-sliding surface 127 of the main shaft 124 is located between the upper end and the lower end of the bearing 134. Therefore, the non-sliding surface 127 is not exposed from the upper end and the lower end of the bearing 134, and both the upper end and the lower end of the bearing 134 are in contact with the sliding surface 126. Note that the sliding surface 126 of the main shaft 124 may constitute a part of the outer circumferential surface in this manner, or may constitute the entire outer circumferential surface of the main shaft 124.

[0045] The compression chamber 133 is formed by inserting the piston 140 reciprocably into a cylindrical bore of the cylinder block 130. The connecting means 142 is formed of, for example, an aluminum casting, and supports the eccentric shaft 122 and is connected to the piston 140. Therefore, the eccentric shaft 122 and the piston 140 are connected by the connecting means 142.

[0046] In the present embodiment, the electric element 104 is an outer rotor type, and the rotor 152 is rotatably arranged coaxially with the stator 150 and surrounding the stator 150. The stator 150 includes a core 160, a coil 162 wound around the core 160, and insulating members 164 provided at the upper and lower ends of the core 160.

[0047] A crank insertion hole 151 is provided in the center of the core 160, and is disposed on the outer periphery of a bearing 134 that supports the crankshaft 120. The core 160 may be fixed to the bearing 134 with a bolt 191, or the crank insertion hole 151 may be fixed to the outer periphery of the bearing 134.

[0048] Rotor 152 includes a disk-shaped frame 153 and a permanent magnet 154 disposed on an inner peripheral end 155 of frame 153. A cylindrical rotor shaft hole 156 is provided in the center of frame 153, and main shaft 124 of crankshaft 120 is inserted into and fixed to rotor shaft hole 156. Therefore, rotor shaft hole 156 can be said to be a support for fixing rotor 152 to crankshaft 120.

[0049] In the first embodiment, the electric element 104 is located on the lower side and the compression element 106 is located on the upper side within the sealed container 102, but the configuration of the compressor 100A according to the present disclosure is not limited to this. That is, the present disclosure also includes a compressor configured such that the electric element is located on the upper side and the compression element is located on the lower side within a sealed container (this also applies to the second or third embodiment described later).

[0050] In compressor 100A configured as described above, first, electric power is supplied from a commercial power source (not shown) to electric element 104, causing rotor 152 of electric element 104 to rotate. Rotor 152 rotates crankshaft 120, and eccentric motion of eccentric shaft 122 is transmitted to piston 140 via connecting means 142, thereby driving piston 140 to reciprocate. Refrigerant gas 181 introduced into sealed container 102 by the reciprocating motion of piston 140 is sucked into compression chamber 133 and compressed.

[0051] The specific driving method of the compressor 100A is not particularly limited. For example, the compressor 100A may be driven by simple on-off control, or may be inverter-driven at a plurality of operating frequencies. That is, the compressor 100A according to the first embodiment may include an inverter circuit so as to be able to rotate and drive the electric element 104 at a plurality of rotational speeds.

[0052] [Fixing the crankshaft and rotor] In the first embodiment, as described above, the frame 153 of the rotor 152 (more specifically, the rotor shaft hole portion 156 provided in the frame 153) is fixed to the main shaft 124 of the crankshaft 120. As shown in FIG. 2, if the part where the main shaft 124 and the rotor shaft hole portion 156 are fixed is defined as a fixed portion 200A, a convex portion 211 is formed on the inner peripheral surface of the rotor shaft hole portion 156 in the fixed portion 200A, and a concave portion 221 that fits closely with the convex portion 211 is formed on the outer peripheral surface (sliding surface 126) of the main shaft 124. Furthermore, a laser irradiation mark 212 is formed on the outer peripheral surface of the rotor shaft hole portion 156 at a position facing the convex portion 211 (a position on the opposite side of the convex portion 211 across the main body of the rotor shaft hole portion 156).

[0053] A method for forming such fixed portion 200A will be described below. First, rotor shaft hole portion 156 is inserted into main shaft 124 of crankshaft 120. During this insertion, main shaft 124 is lightly press-fitted into rotor shaft hole portion 156 so that there is a gap axially downward from the lower end of bearing 134 (see gap 230 (shown in FIG. 4) described later). Here, "lightly press-fitted" refers to a state in which rotor shaft hole portion 156 is slightly deformed by the insertion of main shaft 124, since the outer diameter (diameter) of main shaft 124 is larger than the inner diameter of the shaft hole of rotor shaft hole portion 156.

[0054] With main shaft 124 lightly press-fitted, a laser is irradiated from the outer periphery side of rotor shaft hole 156 toward main shaft 124. The laser irradiation direction at this time is the direction indicated by the "LASER DIRECTION" arrow in Fig. 2, which is a direction perpendicular to the axial direction (dotted line) of main shaft 124. Note that the laser irradiation direction does not have to be perpendicular to the axial direction, and may be approximately perpendicular or intersect with the axial direction.

[0055] As a result, a laser irradiation mark 212 is formed on the outer peripheral surface of rotor shaft hole 156, and a convex portion 211 that protrudes toward main shaft 124 is formed on the inner peripheral surface of rotor shaft hole 156 located in the laser irradiation direction as viewed from laser irradiation mark 212. Also, a concave portion 221 corresponding to the shape of convex portion 211 is formed on the outer peripheral surface (sliding surface 126) of main shaft 124 so as to fit closely with convex portion 211. Due to the fitting state of convex portion 211 and concave portion 221, i.e., the formation of fixing portion 200A, the outer peripheral surface of main shaft 124 is pressed by rotor shaft hole 156, so that main shaft 124 and rotor shaft hole 156 are substantially joined. As a result, rotor 152 is stably fixed to crankshaft 120.

[0056] In the present embodiment 1, crankshaft 120 is made of cast iron, which is an iron alloy with a carbon content of 0.3% or more, and frame 153 of rotor 152 is made of steel, which is an iron alloy with a carbon content of less than 0.3%. Therefore, rotor shaft hole portion 156, which is a part of frame 153, is made of steel.

[0057] In the first embodiment, rotor 152 is an outer rotor type, and frame 153 of rotor 152 is generally formed by pressing a steel plate or the like. As described above, rotor shaft hole 156 is provided in the center of frame 153, but when frame 153 is pressed, rotor shaft hole 156 may be integrally formed with the frame body, or rotor shaft hole 156 molded separately may be attached to frame 153 after it has been molded.

[0058] The crankshaft 120 and the frame 153 are both members of the compressor 100A, but for convenience, the crankshaft 120, which is the member to be fixed (the member to be fixed), will be referred to as the "first member 210," and the rotor shaft hole portion 156, which is the member that fixes (the fixed member or the member to be fixed), will be referred to as the "second member 220." Both the first member 210 and the second member 220 are made of an iron-based material that is iron or an iron alloy, but the iron-based material that makes up the first member 210 has a higher carbon content than the iron-based material that makes up the second member 220.

[0059] Also, second member 220 is fixed to first member 210 by fixing portion 200A, and the surface of first member 210 to which second member 220 is fixed can be referred to as the "fixed surface", and the surface of second member 220 to which first member 210 is fixed can be referred to as the "fixed surface". In this embodiment 1, the inner peripheral surface of rotor shaft hole 156 is the "fixed surface", and the outer peripheral surface of main shaft 124 is the "fixed surface". Furthermore, the surface of second member 220 to which the laser is irradiated can be referred to as the "laser irradiated surface". In rotor shaft hole 156, the outer peripheral surface is the laser irradiated surface.

[0060] When the second member 220 is fixed (joined) to the first member 210, the laser is irradiated to the laser irradiated surface (the outer peripheral surface of the rotor shaft hole 156) of the second member 220 as described above. As a result, the opposite surface to the laser irradiated surface, i.e., the fixing surface of the second member 220 (the inner peripheral surface of the rotor shaft hole 156), is formed by laser processing to form a convex portion 211 that protrudes toward the fixed surface of the first member 210 (the outer peripheral surface of the main shaft 124). In addition, with the formation of this convex portion 211, a concave portion 221 that fits closely to the convex portion 211 is formed on the fixed surface of the first member 210. The convex portion 211 and the concave portion 221 are fitted in a close contact state, and this fitting state is such that the first member 210 and the second member 220 are firmly fixed so as to be substantially joined as described above.

[0061] In the fixing method according to the present disclosure, in order to form the fixing part 200A having the convex part 211 and the concave part 221, the laser is irradiated from a direction opposite to the protruding direction of the convex part 211 in the second member 220. Therefore, the laser irradiation mark 212a is formed on the second member 220 as shown in FIG. 3. For example, in the first embodiment, as shown in the upper diagram of FIG. 3, the linear laser irradiation mark 212a is formed on the outer circumferential surface of the rotor shaft hole part 156 along the circumferential surface of the rotor shaft hole part 156. Note that the upper diagram of FIG. 3 is a side view of the fixing part 200A shown in FIG. 2 as seen from the outside of the rotor shaft hole part 156.

[0062] As shown in the lower diagram of Fig. 3, three laser irradiation marks 212a, 212b, and 212c are formed at approximately equal intervals on the circumferential surface of the rotor shaft hole portion 156. The lower diagram of Fig. 3 is a cross-sectional view (cross-sectional view in the (horizontal) direction perpendicular to the axial direction (vertical direction)) of a portion in the upper diagram of Fig. 3 where the linear laser irradiation mark 212a is formed in the fixed portion 200A. The laser irradiation marks 212a, 212b, and 212c are each the same length, and are formed so as to fit within each region when the circumference of the rotor shaft hole portion 156 is divided into three regions at 120° intervals, as shown in the lower diagram of Fig. 3.

[0063] In the example shown in FIG. 3, as described above, linear protrusions 211 are formed on the opposite surface (fixed surface, inner surface of rotor shaft hole portion 156) to the surface (laser irradiated surface, outer peripheral surface of rotor shaft hole portion 156) on which laser irradiation marks 212a, 212b, 212c are formed in second member 220 (rotor shaft hole portion 156), and linear protrusions 211 are formed on the outer peripheral surface (fixed surface) of first member 210 (main shaft 124) that engage with linear protrusions 211.

[0064] In addition, based on the structure of the fixed part 200A, that is, the state in which the convex part 211 protrudes from the fixed surface of the first member 210, the laser irradiation surface of the second member 220 can be called the surface located on the opposite side to the protruding direction of the convex part 211, that is, the "convex part facing surface". In the present embodiment 1, since the second member 220 is the cylindrical rotor shaft hole part 156, the fixed surface (inner peripheral surface) on which the convex part 211 is formed and the convex part facing surface (laser irradiation surface) face each other in a parallel state. However, the fixed surface and the convex part facing surface (laser irradiation surface) do not have to be parallel to each other, but only need to be in an opposing relationship. In other words, the convex part facing surface may face the fixed surface in a tilted state (for example, see embodiment 3 described later).

[0065] [Fixed part configuration] In the present disclosure, the specific shape of the laser irradiation mark 212, in other words, the specific shapes of the convex portion 211 and the concave portion 221 constituting the fixed portion 200A, are not particularly limited. For example, in the example shown in Fig. 3, the laser irradiation marks 212a to 212c are linear along the outer circumferential surface of the cylindrical rotor shaft hole portion 156 and perpendicular to the axial direction of the cylinder. Therefore, the convex portion 211 is also linear along the inner circumferential surface of the cylindrical rotor shaft hole portion 156 and perpendicular to the axial direction of the cylinder, and the concave portion 221 is also linear along the outer circumferential surface of the cylindrical main shaft 124 and perpendicular to the axial direction of the main shaft 124.

[0066] In contrast, the laser irradiation marks 212 (the convex portions 211 and the concave portions 221) may be in a broken line shape (zigzag shape), a curved shape, or a spot shape (dot shape). The laser irradiation marks 212 (the convex portions 211 and the concave portions 221) may be in a straight line shape, or may be formed in a direction intersecting the axial direction rather than perpendicularly, or may be formed in parallel to the axial direction (up and down direction).

[0067] 3, three laser irradiation marks 212a, 212b, and 212c are formed, so that three fixed portions 200A (protrusions 211 and recesses 221) are also formed. However, the number of laser irradiation marks 212 or fixed portions 200A (protrusions 211 and recesses 221) is not limited to this. For example, one linear laser irradiation mark 212 (fixed portion 200A) may be formed around the entire circumference of the outer circumferential surface of the rotor shaft hole portion 156 (second member 220), two or four or more laser irradiation marks 212 (fixed portion 200A) may be formed, or multiple spot-shaped laser irradiation marks 212 (fixed portion 200A) may be formed around the entire circumference.

[0068] 3, the positions where the laser irradiation marks 212a-212c are formed are positions along the center in the up-down direction (axial direction) on the outer peripheral surface of the rotor shaft hole portion 156 (second member 220). Therefore, the positions where the convex portions 211 are formed are positions along the center in the up-down direction on the inner peripheral surface, but the positions where the laser irradiation marks 212 are formed (the positions where the convex portions 211 or the fixed portion 200A are formed) are not limited to this. For example, they may be unevenly distributed on the upper side or the lower side in the up-down direction, or they may be a mixture of central positions and unevenly distributed positions.

[0069] Thus, the specific configuration of the laser irradiation marks 212, i.e., the fixing portion 200A, is not particularly limited, but as an example of a preferred configuration, as shown in FIG. 3, three or more identically shaped laser irradiation marks 212 (fixing portion 200A) are formed at equal intervals. In such a configuration, since a plurality of laser irradiation marks 212 are formed at equal intervals, it is possible to realize good strength (or good holding force) for fixing the crankshaft 120 to the rotor 152. In addition, since the amount of heat applied to the rotor shaft hole portion 156, which is the second member 220, by the laser irradiation can be dispersed, it is possible to effectively suppress or avoid the risk of the second member 220 being deformed by heat. Therefore, it is possible to realize good quality retention.

[0070] Furthermore, even when a large centrifugal force acts on the rotor 152 due to high-speed operation of the compressor 100A, or when a large torque is generated due to the rotor 152 suddenly stopping, the laser irradiation marks 212, i.e., the fixed portions 200A, are formed, preferably at equal intervals, so that the rotor 152 is firmly fixed (held) to the crankshaft 120. This makes it possible to prevent the rotor 152 from shifting from the fixed position of the crankshaft 120. This makes it possible to effectively suppress a decrease in durability of the compressor 100A, and achieves good reliability.

[0071] Here, the conditions for high-speed operation of compressor 100A are not particularly limited, but for example, a standard for high-speed operation can be a rotation speed of 60 rps or more of crankshaft 120. If the rotation speed of crankshaft 120 is 60 rps or more, as described above, a large centrifugal force acts on rotor 152, and if crankshaft 120 suddenly stops from this high-speed operating state, a large torque is likely to be generated in rotor 152.

[0072] Alternatively, as an example of another preferred configuration of the laser irradiation mark 212 (fixing portion 200A), a configuration in which one linear laser irradiation mark 212 is formed over the entire circumference can be cited. In this configuration, it is only necessary to irradiate the laser linearly according to the shape of the second member 220, so that the second member 220 can be fixed to the first member 210 without using a special program or tool for laser irradiation. Therefore, it is possible to improve productivity.

[0073] Alternatively, as an example of yet another preferred configuration of the laser irradiation marks 212 (fixing portion 200A), a configuration in which a plurality of laser irradiation marks 212 parallel to the axial direction (vertical direction) can be formed can be given. With this configuration, the laser can be irradiated with high density onto the laser irradiation surface of the second member 220 (the formation density of the convex portions 211 and concave portions 221 constituting the fixing portion 200A can be increased), so that the fixing strength of the second member 220 to the first member 210 can be improved.

[0074] 2, the laser irradiation marks 212 are illustrated as being recessed (concave) from the outer circumferential surface of the second member 220 (rotor shaft hole portion 156), but in the present disclosure, the laser irradiation marks 212 are not necessarily formed as concaves. The laser irradiation marks 212 may be marks on the surface of the second member 220 where the iron-based material constituting the second member 220 has melted at the position irradiated with the laser.

[0075] As a representative example of the fixed portion 200A according to the present disclosure, a laser microscope photograph of the fixed portion 200A is shown in Fig. 4. The fixed portion 200A shown in Fig. 4 is formed by irradiating the rotor shaft hole portion 156 (second member 220) of the rotor 152 with a laser relative to the main shaft 124 (first member 210) of the crankshaft 120. The circumferential shape of this fixed portion 200A is a straight line of about 10 mm, and similarly to Fig. 3, three fixed portions 200A are formed at equal intervals within an angular range of 120°.

[0076] In the fixed part 200A shown in Fig. 4, the main shaft 124 as the first member 210 is made of cast iron with a carbon content of 0.3% or more, and the rotor shaft hole portion 156 as the second member 220 is made of steel with a carbon content of less than 0.3%. The thickness of the rotor shaft hole portion 156 as the second member 220 is 0.95 mm. The laser used is a fiber laser with an output of 3000 W.

[0077] When the fixed part 200A was cut along the axial direction (vertical direction) and the cut surface was observed with a laser microscope, as shown in Fig. 4, a convex part 211 of about 0.1 mm was formed on the inner peripheral surface of the rotor shaft hole part 156, which is the second member 220, and a concave part 221 corresponding to the convex part 211 was formed on the outer peripheral surface of the main shaft 124, which is the first member 210. In Fig. 4, the convex part 211 and the concave part 221 constituting the fixed part 200A are closely fitted together, and on the upper side of the fixed part 200A, the outer peripheral surface of the first member 210 and the inner peripheral surface of the second member 220 are closely fitted together. In contrast, a gap 230 is formed on the lower side of the fixed part 200A.

[0078] As described above, when the inner diameter of rotor shaft hole 156 is smaller than the outer diameter of main shaft 124 and main shaft 124 is "lightly press-fitted" into rotor shaft hole 156, theoretically, gap 230 does not occur between the outer peripheral surface of main shaft 124 and the inner peripheral surface of rotor shaft hole 156. However, depending on the manufacturing tolerance of main shaft 124 and rotor shaft hole 156, gap 230 of about several microns may occur, as shown below fixed portion 200A in Fig. 4. Even if gap 230 occurs between first member 210 and second member 220 in this way, these members can be satisfactorily fixed together as long as fixed portion 200A is formed by laser irradiation.

[0079] As described later, in the present disclosure, the fixing portion 200A described above is formed on the contact surface between the second member 220 and the first member 210, i.e., the inner surface of the second member 220, by irradiating the outer surface of the second member 220 with a laser. Therefore, among the convex portion 211 and the concave portion 221 constituting the fixing portion 200A, at least the convex portion 211 formed on the inner side of the second member 220, which is the target of laser irradiation, can be regarded as a "laser irradiation deformed portion" that is directly generated by laser irradiation. In addition, the concave portion 221 formed on the first member 210, which is not the direct target of laser irradiation, can be regarded as an "indirectly deformed portion" that is indirectly formed with the formation of the convex portion 211, which is the laser irradiation deformed portion.

[0080] Therefore, by defining the dimensions (size) of the protrusions 211 which are the laser irradiation deformation parts, it is possible to define the dimensions of the recesses 221 which are the indirect deformation parts. The specific dimensions of the protrusions 211 are not particularly limited, and the dimensions will vary depending on various conditions such as the specific configuration of the second member 220 which is the laser irradiation target, the type of laser to be irradiated, or the specific configuration of the first member 210 which is in contact with the second member 220.

[0081] For example, in the second member 220, the surface on which the convex portion 211 is formed, i.e., the surface fixed to the first member 210, and the surface to be irradiated with the laser, i.e., the laser irradiated surface, are in a positional relationship facing each other, but the distance between the fixed surface and the laser irradiated surface in the second member 220 is not particularly limited. As described in the first embodiment, if the second member 220 is the rotor shaft hole portion 156, its outer peripheral surface is the laser irradiated surface, and its inner peripheral surface is the fixed surface. Therefore, the distance between the fixed surface and the laser irradiated surface coincides with the thickness of the rotor shaft hole portion 156.

[0082] As described above, the thickness of rotor shaft hole 156 is 0.95 mm, but the distance between the fixed surface and the laser irradiation surface is not limited to this and can be, for example, within a range of 0.5 mm to 3 mm, depending on various conditions. If the distance between the fixed surface and the laser irradiation surface is within this suitable range, it is possible to form convex portion 211 even with a small output during laser irradiation. This makes it possible to effectively suppress the possibility of deformation, etc. occurring in fixed portion 200A and its surrounding areas due to the influence of heat from laser irradiation.

[0083] On the other hand, if the distance (thickness) between the fixing surface and the laser irradiated surface is too small, the first member 210 and the second member 220 may melt due to the heat of the laser before the protrusion 211 is formed. If the distance (thickness) between the fixing surface and the laser irradiated surface is too large, there is a risk that a good protrusion 211 will not be formed on the fixing surface even if the laser is irradiated to the laser irradiated surface.

[0084] When the surface of first member 210 to which second member 220 is fixed, i.e., the surface in contact with the fixing surface of second member 220, is taken as the fixed surface, the amount of protrusion of convex portion 211 from the fixing surface of second member 220 to the fixed surface of first member 210 is not particularly limited. As described above, when first member 210 is main shaft 124, the outer circumferential surface of main shaft 124 is the fixed surface, and second member 220 is rotor shaft hole portion 156, sufficient strength can be achieved if convex portion 211 is about 0.1 mm. The amount of protrusion can be set appropriately depending on the conditions of laser irradiation, and is not limited to about 0.1 mm.

[0085] In the present disclosure, in evaluating the dimensions of the protrusion 211, the ratio of the protrusion amount (height) to the width of the protrusion 211 can be suitably used rather than the protrusion amount of the protrusion 211. If the ratio of the protrusion amount to the width of the protrusion 211 is defined as the "protrusion ratio," a representative protrusion ratio may be within the range of, for example, 0.20 to 0.55, and a preferred range may be within the range of, for example, 0.23 to 0.50.

[0086] If the protrusion ratio is less than 0.20, depending on various conditions, the protrusion amount (height) of the protrusion 211 relative to the width may be too small, and the first member 210 and the second member 220 may not be fixed well. On the other hand, if the protrusion ratio exceeds 0.55, depending on various conditions, it may be necessary to make the laser irradiation energy very strong, and the formation efficiency of the protrusion 211 (i.e., the efficiency of the fixing work of the first member 210 and the second member 220) may decrease. Also, depending on various conditions, depending on the shape or material of each member, the thickness of the second member 220 (the distance between the fixing surface and the laser irradiation surface), the laser irradiation conditions, etc., it may not be possible to form the protrusion 211 with a protrusion ratio exceeding 0.55.

[0087] [Manufacturing method of compressor] Next, a representative example of a method for manufacturing the compressor 100A including a step of forming the fixing portion 200A will be described. In the method for manufacturing the compressor according to the present disclosure (hereinafter, appropriately abbreviated as the manufacturing method), when fixing the first member 210 and the second member 220 provided in the compressor 100A, the protrusion 211 is formed on the second member 220 using a laser as described above. In addition, both the first member 210 and the second member 220 are made of an iron-based material that is iron or an iron alloy, but the iron-based material that makes up the second member 220 has a lower carbon content than the iron-based material that makes up the first member 210.

[0088] As described above, the surface of the second member 220 that is to be fixed to the first member 210 is referred to as the fixing surface, and the surface of the first member 210 to which the second member 220 is fixed is referred to as the fixed surface. In the manufacturing method according to the present disclosure, first, the fixing surface of the second member 220 is abutted against the fixed surface of the first member 210. Then, in this state, a laser is irradiated from an outer surface (opposing surface) facing the fixing surface of the second member 220 toward the fixing surface. As a result, a convex portion 211 that protrudes toward the fixed surface of the first member 210 is formed on the fixing surface of the second member 220, and a concave portion 221 that fits closely with the convex portion 211 is formed on the fixed surface of the first member 210.

[0089] In this way, forming the convex portion 211 on the fixing surface of the second member 220 by irradiating a laser means that the convex portion 211 is driven into the fixed surface of the first member 210. Accordingly, a concave portion 221 corresponding to the shape of the convex portion 211 is formed on the fixed surface of the first member 210. Therefore, the fixed surface of the first member 210 is joined by being pressed by the convex portion 211 on the fixing surface of the second member 220. As a result, the second member 220 can be fixed to the first member 210 satisfactorily.

[0090] The laser irradiation device used in the manufacturing method according to the present disclosure is not particularly limited, and various known laser irradiation devices such as a gas laser, a semiconductor laser, and a solid-state laser can be used. Typically, a fiber laser can be preferably used as described above. A fiber laser is a type of solid-state laser, and since it uses an optical fiber as a medium, it has advantages such as high energy conversion efficiency, easy to increase the output, easy to make the focal point small, and excellent beam quality.

[0091] The laser irradiation conditions when irradiating the second member 220 with a laser are not particularly limited. For example, the laser output may be 5000 W or less, and is preferably 3000 W or less. In the example shown in FIG. 2, the laser irradiation angle is perpendicular or approximately perpendicular to the laser irradiation surface (outer peripheral surface) of the second member 220 (rotor shaft hole portion 156), but the irradiation angle is not limited thereto. For example, a predetermined angle may be set with respect to the normal direction of the outer peripheral surface, and the laser may be irradiated in an inclined state. Even if there is no space available on the laser irradiation surface of the second member 220, the laser can be irradiated so as to form the convex portion 211 on the fixing surface by appropriately setting the laser irradiation angle.

[0092] In the manufacturing method according to the present disclosure, there is no particular limitation on the specific configuration of the first member 210 and the second member 220. In the first embodiment, the first member 210 is the crankshaft 120, and the second member 220 is the support portion of the rotor 152 fixed to the crankshaft 120, i.e., the rotor shaft hole portion 156, but the present invention is not limited thereto, and the second member 220 may be a balance weight 171 fixed to the crankshaft 120, as exemplified in the second embodiment described later.

[0093] Alternatively, the chamber part of the compressor 100A may be the first member 210, and the lid member closing the opening of the chamber part may be the second member 220. The chamber part forms a buffer space for reducing pulsation of the compressed refrigerant gas 181 during operation of the compressor 100A. The opening of the chamber part is closed by the lid member, and a fastening member such as a bolt is used for this purpose. By irradiating a laser from the outer surface (laser irradiated surface) of the lid member instead of the fastening member, a convex part 211 can be formed on the abutting surface (fixing surface) of the lid member, and accordingly, a concave part 221 can be formed on the edge part (fixed surface) of the opening of the chamber part.

[0094] If the first member 210 is the main shaft 124 of the crankshaft 120 and the second member 220 is the rotor shaft hole portion 156 of the rotor 152 as in the present embodiment 1, the manufacturing method according to the present disclosure can firmly fix the rotor 152 to the crankshaft 120 in a simple manner.

[0095] The rotor shaft hole 156 of the rotor 152 is generally fixed to the main shaft 124 by welding, shrink fitting, press fitting, etc. However, when welding is performed on cast iron containing a large amount of carbon, the cast iron becomes molten due to the heat generated during welding, and is easily turned into white iron when rapidly cooled thereafter. When white iron is produced at the welded portion, a difference in contraction occurs between the welded portion and the base material, and large residual stress occurs. Furthermore, white iron is hard and brittle, and is therefore easily cracked. Therefore, if the main shaft 124 is made of cast iron, it is substantially difficult to fix the rotor shaft hole 156 by welding.

[0096] In addition, in order to use shrink fitting or press fitting, it is necessary to increase the axial length or thickness of the rotor shaft hole 156. If the rotor 152 is an outer rotor type, the moment of inertia is larger than that of an inner rotor type rotor. Therefore, the holding force of the rotor 152 with respect to the main shaft 124 needs to be relatively strong. In order to ensure a strong holding force by shrink fitting or press fitting, as described above, the axial length of the rotor shaft hole 156 is increased (the shrink fitting area or press fitting area is increased), or the thickness of the rotor shaft hole 156 itself is increased to further improve its strength. As a result, the fixing portion of the rotor 152 becomes bulky, which may hinder the miniaturization of the compressor 100A.

[0097] In contrast, in the manufacturing method according to the present disclosure, a laser is irradiated from the outer circumferential surface (laser irradiated surface) of rotor shaft hole 156, so that convex portions 211 are formed so as to be driven from the inner circumferential surface (fixed surface) of rotor shaft hole 156 into the outer circumferential surface (fixed surface) of main shaft 124. Accordingly, concave portions 221 having a shape corresponding to convex portions 211 are formed on the outer circumferential surface of main shaft 124, so that in fixed portion 200A, the outer circumferential surface of main shaft 124 is pressed from the inner circumferential surface of rotor shaft hole 156. This allows rotor 152 to be held satisfactorily relative to crankshaft 120.

[0098] Moreover, in the manufacturing method according to the present disclosure, a strong fixed state (joined state) can be achieved simply by partially forming the protrusions 211 by laser irradiation. Therefore, compared to shrink fitting or press fitting, there is no need to increase the axial length or thickness of the rotor shaft hole portion 156. This makes it possible to avoid increasing the size of the compressor 100A and promote miniaturization. Also, compared to shrink fitting, there is no need for large, special manufacturing equipment (such as a heating furnace and a drying furnace), so it is possible to avoid the manufacturing equipment becoming larger or more complicated.

[0099] Furthermore, in the manufacturing method according to the present disclosure, since it is only necessary to locally irradiate the laser to the portion to be fixed (joined), it is possible to suppress the amount of heat given to the first member 210 and the second member 220. This makes it possible to effectively suppress the occurrence of thermal effects on the first member 210 or the second member 220. For example, it is possible to suppress or avoid the risk of thermal deformation of the insulating member 164, the frame 153, or the rotor shaft hole portion 156 itself provided on the rotor 152, or thermal deformation of the periphery of the fixed surface of the main shaft 124. Therefore, it is possible to further improve the quality of the portion where the rotor 152 is fixed to the crankshaft 120.

[0100] In the first embodiment, as described above, the compressor 100A may be inverter-driven, and the electric element 104 may be driven at a plurality of rotation speeds. Therefore, the compressor 100A can be operated with high reliability from a low rotation speed range to a high rotation speed range.

[0101] For example, during low speed operation, torque fluctuations occurring when the refrigerant is compressed cause a large force to act in the rotational direction between crankshaft 120 and rotor 152. According to the present disclosure, since fixing portion 200A described above is formed between rotor shaft hole portion 156 and main shaft 124, rotor 152 is firmly fixed to crankshaft 120. Therefore, even during low speed operation with large torque fluctuations, it is possible to effectively prevent rotor 152 from shifting from the position where it is fixed to crankshaft 120.

[0102] Furthermore, during high speed operation, a large centrifugal force acts on rotor 152. According to the present disclosure, since fixing portion 200A described above is formed between rotor shaft hole portion 156 and main shaft 124, rotor 152 is firmly fixed to crankshaft 120. Therefore, even if a large centrifugal force acts on rotor 152, the risk of rotor 152 being displaced from the position where it is fixed to crankshaft 120 can be effectively prevented.

[0103] As a result, in the compressor 100A according to the present disclosure, the durability of the portion where the rotor 152 is fixed to the crankshaft 120 is dramatically improved, so that the reliability of the compressor 100A can be further improved.

[0104] (Embodiment 2) In the compressor 100A according to the first embodiment, the first member 210 is the main shaft 124 of the crankshaft 120, and the second member 220 is the rotor shaft hole portion 156 (fixed support portion of the rotor 152) of the outer rotor type rotor 152, but the present disclosure is not limited to this. In the second embodiment, as shown in Fig. 5, an example will be described in which the first member 210 is the flange 128 of the crankshaft 120, and the second member 220 is the balance weight 172.

[0105] 5, the compressor 100B according to the second embodiment has substantially the same configuration as the compressor 100A according to the first embodiment (see FIG. 1) except for the balance weight 172. Therefore, a description of the specific configuration and operation of the compressor 100B will be omitted.

[0106] 1, in compressor 100A, balance weight 171 is fixed to the upper end of eccentric shaft 122 of crankshaft 120. In contrast, in compressor 100B, balance weight 172 is fixed to the upper surface of flange 128 of crankshaft 120. In this way, in order to reduce the load imbalance in crankshaft 120, the fixing positions of balance weights 171, 172 are not particularly limited (for example, they may be attached to electric element 104).

[0107] The flange 128 is made of an iron-based material having a carbon content of 0.3% or more, similar to the main shaft 124 of the crankshaft 120, and the balance weight 172 is made of an iron-based material having a carbon content of less than 0.3%. Therefore, the manufacturing method of the compressor described in the first embodiment can be applied.

[0108] Specifically, as shown in Fig. 6, the flange 128 is the first member 210, and the balance weight 172 is the second member 220. In the example shown in Fig. 6, the balance weight 172 is fixed to the upper surface of the flange 128. Therefore, the upper surface of the flange 128 is the fixed surface of the first member 210, the lower surface (second surface, back surface) of the balance weight 172 is the fixed surface, and the upper surface (first surface, front surface) of the balance weight 172 is the laser irradiated surface (or the surface facing the convex portion).

[0109] Therefore, as shown in Fig. 6, a laser is irradiated from the top surface (laser irradiation surface) of balance weight 172 in the direction of the arrow "LASER DIRECTION" in the figure. In Fig. 6, the laser irradiation direction is a direction parallel to the axial direction of crankshaft 120 (dotted line in the figure), and corresponds to the normal direction (vertical direction) when viewed from the top surface of balance weight 172. As described in the first embodiment, the laser irradiation direction is not particularly limited.

[0110] As a result, laser irradiation marks 214 are formed on the upper surface (laser irradiated surface) of the balance weight 172, and a convex portion 213 that protrudes toward the upper surface (fixed surface) of the flange 128 is formed on the lower surface (fixed surface) of the balance weight 172. That is, the convex portion 213 is formed so as to be driven from the balance weight 172, which is the second member 220, to the flange 128, which is the first member 210. Accordingly, a concave portion 223 having a shape corresponding to the convex portion 213 is formed on the upper surface of the flange 128. As a result, a fixed portion 200B is formed, which is composed of the convex portion 213 and the concave portion 223 that fits closely thereto.

[0111] In the fixing portion 200B, similarly to the fixing portion 200A in the first embodiment, the flange 128 is pressed by the protruding portion 213 of the balance weight 172, thereby fixing (joining) the flange 128. Therefore, the balance weight 172 is firmly fixed to the flange 128.

[0112] The position where the convex portion 213 is formed, i.e., the position where the laser irradiation mark 214 is formed, is not particularly limited. In the example shown in Fig. 6, the laser is irradiated near the center of the upper surface of the balance weight 172, but it may be irradiated to the peripheral portion or the entire surface.

[0113] In addition, since the thickness of balance weight 172 is 1.6 mm in this embodiment 2, the distance between the fixed surface and the laser irradiation surface of second member 220 is 1.6 mm in this embodiment 2, but is of course not limited to this. Although it depends on various conditions, the distance between the fixed surface and the laser irradiation surface can be preferably, for example, within the above-mentioned range of 0.5 mm to 3 mm, so the thickness of balance weight 172 may also be within this range.

[0114] Other than these, the specific configuration of the fixed portion 200B or the laser irradiation mark 214 is similar to the configuration example of the fixed portion 200A or the laser irradiation mark 212 described in the first embodiment, so a detailed description thereof will be omitted.

[0115] Moreover, the compressor 100B according to the second embodiment can be manufactured by the manufacturing method of the compressor according to the present disclosure described in the first embodiment. Therefore, in the second embodiment, a detailed description of the manufacturing method of the compressor will be omitted.

[0116] If the first member 210 is the flange 128 of the crankshaft 120 and the second member 220 is the balance weight 172 as in this embodiment 2, the manufacturing method of the present disclosure can firmly fix the balance weight 172 to the flange 128 in a simple manner.

[0117] For the purpose of reducing the load imbalance in the crankshaft 120, generally, as in the compressor 100A according to the first embodiment, the balance weight 171 is fixed to the tip (upper end) of the eccentric shaft 122 (see FIG. 1). However, in this configuration, the height (size in the vertical direction) of the compression element 106 is affected by the balance weight 171. That is, if the thickness of the balance weight 171 is large, the height of the compression element 106 including the crankshaft 120 may become large, which will affect the miniaturization or low-profile of the compressor 100A.

[0118] Therefore, in the past, when the balance weight 172 was fixed to the upper surface of the flange 128, generally, caulking using a fastening member such as a rivet pin or welding was used.

[0119] However, when fixing by crimping, a fastening member such as a rivet pin is required separately, so the number of parts increases. Also, it is necessary to form through holes for inserting the fastening members in the flange 128 and the balance weight 172. Therefore, depending on the shapes of the flange 128 and the balance weight 172, the positions of the through holes are limited, so the degree of freedom of the fixing position is limited.

[0120] Furthermore, when fixing by welding, as described in the first embodiment, welding cast iron containing a large amount of carbon causes white pig iron. Therefore, just as in the case where the main shaft 124 is made of cast iron, if the flange 128 is also made of cast iron, it is substantially difficult to fix the balance weight 172 by welding.

[0121] In contrast, in the manufacturing method according to the present disclosure, a laser is irradiated from the upper surface (laser irradiated surface) of the balance weight 172, so that a convex portion 213 is formed so as to be driven from the lower surface (fixing surface) of the balance weight 172 into the upper surface (fixed surface) of the flange 128. Accordingly, a concave portion 223 having a shape corresponding to the convex portion 213 is formed on the outer circumferential surface of the flange 128, so that at the fixing portion 200B, the upper surface of the flange 128 is pressed from the lower surface of the balance weight 172. This allows the balance weight 172 to be fixed to the crankshaft 120 satisfactorily.

[0122] Moreover, in the manufacturing method according to the present disclosure, a strong fixed state (joined state) can be realized by only partially forming the convex portion 213 by laser irradiation. Therefore, the balance weight 172 can be fixed to the flange 128 with a high degree of freedom compared to crimping with a rivet pin or the like. Therefore, as shown in FIG. 6, the balance weight 172 can be fixed not only to the upper surface of the flange 128 but also to the side surface or lower surface of the flange 128. This makes it possible to reduce the unbalance of the load while suppressing the height increase of the compression element 106. Therefore, it is possible to promote the miniaturization of the compressor 100B.

[0123] (Embodiment 3) In the compressor 100A according to the first embodiment or the compressor 100B according to the second embodiment, the electric element 104 is of the outer rotor type, but the present disclosure is not limited to this. In the third embodiment, as shown in FIG. 7, a compressor 100C is configured to include an electric element 105 of an inner rotor type.

[0124] 7, the compressor 100C according to the third embodiment has substantially the same configuration as the compressor 100A according to the first embodiment (see FIG. 1) except that the electric element 105 is an inner rotor type. Therefore, a description of the specific configuration and operation of the compressor 100C will be omitted.

[0125] 7, the electric motor element 105 is composed of at least a stator 157 and a rotor 158. The stator 157 is fixed to the lower side of the cylinder block 130 included in the compression element 106 by fasteners such as bolts (not shown), and the rotor 158 is disposed inside the stator 157 and coaxially with the stator 157. The rotor 158 is fixed to the main shaft 124 of the crankshaft 120 included in the compression element 106, similar to the outer rotor type rotor 152 in the first embodiment.

[0126] 8, if the portion where the main shaft 124 and the rotor 158 are fixed is defined as fixed portion 200C, this fixed portion 200C has a convex portion 215 formed on the inner peripheral surface of the lower side of rotor 158, and a concave portion 225 that fits closely with this convex portion 215 formed on the outer peripheral surface (sliding surface 126) of main shaft 124. Furthermore, laser irradiation marks 216 are formed on the lower surface of rotor 158 at a position close to main shaft 124.

[0127] Therefore, in the third embodiment, the main shaft 124 is the first member 210, and the portion of the rotor 158 that abuts against the main shaft 124 is the second member 220. Moreover, the outer circumferential surface of the main shaft 124 is the fixed surface of the first member 210, the inner circumferential surface on the lower side of the rotor 158 is the fixed surface, and the lower surface of the rotor 158 is the laser irradiated surface (or the surface facing the convex portion). Furthermore, it can be said that the portion of the lower part of the rotor 158 that abuts against the outer circumferential surface of the main shaft 124 is a support portion of the rotor 158 that is fixed to the crankshaft 120.

[0128] 8, a laser is irradiated from a position close to the main shaft 124 to the underside (laser irradiated surface) of the rotor 158 in an oblique direction toward the main shaft 124 as indicated by the arrow "LASER DIRECTION" in the figure. As a result, laser irradiation marks 216 are formed on the underside of the rotor 158, convex portions 215 are formed on the inner peripheral surface of the rotor 158, and concave portions 225 are formed on the outer peripheral surface of the main shaft 124.

[0129] That is, the convex portion 215 is formed so as to be driven from the rotor 158, which is the second member 220, to the main shaft 124, which is the first member 210. Accordingly, a concave portion 225 having a shape corresponding to the convex portion 215 is formed on the outer circumferential surface of the main shaft 124. As a result, a fixing portion 200C is formed, which is constituted by the convex portion 215 and the concave portion 225 which fits closely thereto. In this fixing portion 200C, the main shaft 124 is fixed (joined) by being pressed by the convex portion 215 of the rotor 158, similarly to the fixing portion 200A in the first embodiment or the fixing portion 200B in the second embodiment. Therefore, the rotor 158 is firmly fixed to the main shaft 124.

[0130] In the first embodiment, the second member 220 is the cylindrical rotor shaft hole portion 156, and in the second embodiment, the second member 220 is the flat balance weight 172. Therefore, the laser irradiation surface of the second member 220, i.e., the surface facing the convex portion, is in a mutually parallel positional relationship with the fixed surface on which the convex portion 211 is formed.

[0131] In contrast, in the third embodiment, the inner circumferential surface of the rotor 158, which is the fixed surface, and the lower surface of the rotor 158, which is the laser irradiation surface, i.e., the convex portion facing surface, are in a mutually perpendicular positional relationship. In other words, it can be said that the convex portion facing surface (lower surface) is inclined so as to form a right angle with respect to the fixed surface (inner circumferential surface). Therefore, in the present disclosure, as explained in the first embodiment, the fixed surface and the convex portion facing surface (laser irradiation surface) may not be parallel to each other, and may face each other with one surface inclined. In other words, the convex portion facing surface (laser irradiation surface) of the second member 220 may be an outer surface located in the normal direction of the fixed surface of the second member 220 or in a direction inclined from the normal direction.

[0132] In the second member 220, the position where the convex portion 215 is formed on the fixing surface and the position where the laser irradiation mark 216 is formed on the laser irradiated surface (the surface facing the convex portion) are in a positional relationship that faces each other with the laser irradiation direction as a reference. In other words, if the position of the convex portion 215 on the fixing surface is used as a reference, the position of the laser irradiation mark 216 on the laser irradiated surface (the surface facing the convex portion) corresponds to the position projected on the opposite side of the protruding direction of the convex portion 215 (the opposite side of the laser irradiation direction).

[0133] In the first embodiment or the second embodiment, as described above, the fixing surface and the laser irradiation surface (the surface facing the convex portion) are in a parallel positional relationship. Therefore, it is clear from Fig. 2 or 6 that the position of the laser irradiation mark 212 on the convex portion 211 in the first embodiment and the position of the laser irradiation mark 214 on the convex portion 213 in the second embodiment are both in a relationship of facing each other with the main body (base material) of the second member 220 in between.

[0134] On the other hand, in the third embodiment, the laser irradiation surface (the surface facing the convex portion) is in a positional relationship of "inclined" with respect to the fixed surface (in other words, a positional relationship in which a first surface including the fixed surface and a second surface including the laser irradiation surface intersect). If the laser irradiation direction is taken as a reference, it is clear that they are in an opposing positional relationship, but in order to define the structural positional relationship without taking the laser irradiation direction as a reference, another reference is required. Therefore, in the third embodiment, the position of the laser irradiation mark 216 on the surface facing the convex portion (lower surface) is defined as the position of the convex portion 215 on the fixed surface (inner peripheral surface) projected on the opposite side of the protruding direction of the convex portion 215.

[0135] The position of the laser irradiation mark 212 on the convex portion facing surface in the first embodiment can be defined as the position of the convex portion 211 on the fixing surface projected on the opposite side in the protruding direction of the convex portion 211, as in the third embodiment. The position of the laser irradiation mark 214 on the convex portion facing surface in the second embodiment can be defined as the position of the convex portion 213 on the fixing surface projected on the opposite side in the protruding direction of the convex portion 213.

[0136] The action and effect of the fixed portion 200C in this embodiment 3, the details of the method for forming the fixed portion 200C (the method for manufacturing the compressor) and the action and effect thereof are similar to those of the first or second embodiment, and therefore will not be described again.

[0137] (Embodiment 4) In this embodiment 4, an example of a refrigeration / refrigeration device equipped with compressor 100A described in embodiment 1, compressor 100B described in embodiment 2, or compressor 100C described in embodiment 3 will be specifically described with reference to FIG. 9.

[0138] The compressors 100A to 100C according to the present disclosure can be widely and suitably used in various devices (freezing and refrigeration devices) having a refrigeration cycle or a configuration substantially equivalent thereto. Specific examples include, but are not limited to, refrigerators (household refrigerators, commercial refrigerators), ice makers, showcases, dehumidifiers, heat pump water heaters, heat pump washer-dryers, vending machines, air conditioners, and air compressors. In the fourth embodiment, the basic configuration of a freezing and refrigeration device will be described by taking an article storage device shown in FIG. 9 as an application example of the compressors 100A to 100C according to the present disclosure.

[0139] As shown in Fig. 9, the refrigeration / freezing device according to the fourth embodiment includes a main body 301, a partition wall 304, and a refrigerant circuit 305. The main body 301 is composed of a heat-insulating box and a door, one side of which is open, and the door opens and closes the opening of the box. The inside of the main body 301 is partitioned by the partition wall 304 into an item storage space 302 and a machine room 303. A blower (not shown) is provided in the storage space 302. The inside of the main body 301 may be partitioned into spaces other than the storage space 302 and the machine room 303.

[0140] The refrigerant circuit 305 is configured to cool the inside of the storage space 302, and includes, for example, the compressor 100A described in the first embodiment, the compressor 100B described in the second embodiment, or the compressor 100C described in the third embodiment, a radiator 307, a pressure reducing device 308, and a heat absorber 309, which are connected in a ring shape by piping. In other words, the refrigerant circuit 305 is an example of a refrigeration cycle using the compressor 100A, 100B, or 100C according to the present disclosure.

[0141] The heat absorber 309 is disposed in the storage space 302. The cooling heat of the heat absorber 309 is stirred by a blower (not shown) so as to circulate within the storage space 302, as shown by the dashed arrows in Fig. 3. This causes the inside of the storage space 302 to be cooled.

[0142] As described above, the refrigeration / freezing device according to the fourth embodiment is equipped with the compressor 100A according to the first embodiment, the compressor 100B according to the second embodiment, or the compressor 100C according to the third embodiment. In these compressors 100A to 100C, the second member 220 is fixed to the first member 210 by the fixing part 200A composed of the convex part 211 and the concave part 221, the fixing part 200B composed of the convex part 213 and the concave part 223, or the fixing part 200C composed of the convex part 215 and the concave part 225.

[0143] The convex portions 211, 213, 215 are all formed by laser processing on the fixing surface of the second member 220 and protrude relative to the fixed surface of the first member 210, and the concave portions 221, 223, 225 are all tightly fitted into the convex portion 211 on the fixed surface of the first member 210. The convex portions 211, 213, 215 and the concave portions 221, 223, 225 can be easily formed substantially in one step by laser processing, and the state of the fixing portions 200A to 200C in which the convex portions 211, 213, 215 and the concave portions 221, 223, 225 are tightly fitted into each other is sufficiently stable, so that the second member 220 can be satisfactorily fixed to the first member 210.

[0144] According to such a fixing structure, the first member 210 and the second member 220 of the compressors 100A to 100C can be fixed satisfactorily without shrink fitting or the like, and the increase in the fixing area can be reduced compared to shrink fitting. Therefore, in the compressors 100A to 100C, it is possible to realize good quality retention and effectively avoid the risk of preventing miniaturization.

[0145] (Embodiment 5) In the above-mentioned first to fourth embodiments, the second member is fixed to the first member of the compressor, but the present disclosure is not limited to this. That is, the present disclosure is not limited to the compressor field, but also includes a method of joining a second member to a first member made of an iron-based material, that is, a method of joining iron-based members.

[0146] The method for joining iron-based members according to the present disclosure may be a method used for joining a first member made of an iron-based material such as iron or an iron alloy to a second member made of an iron-based material having a lower carbon content than the iron-based material constituting the first member. There are no particular limitations on the type of iron-based material, the types of the first member and the second member, the uses of the first member and the second member, etc.

[0147] In the method for joining iron-based members according to the present disclosure, a laser is irradiated from an outer surface (laser irradiated surface or convex portion facing surface in the first to third embodiments) opposite to the joining surface (fixed surface in the first to third embodiments) of the second member toward the surface to be joined of the first member (fixed surface in the first to third embodiments). As a result, a convex portion that protrudes toward the surface to be joined of the first member is formed on the joining surface of the second member, and a concave portion is formed on the surface to be joined of the first member in conjunction with the formation of the convex portion. Therefore, the concave portion and the convex portion fit together in a tight contact state.

[0148] As described in the first or third embodiment, the outer surface (laser irradiated surface or convex portion facing surface) of the second member opposite the joining surface may be a surface (facing surface) opposite the joining surface (fixing surface) of the second member, and the positional relationship between the joining surface and the outer surface does not necessarily have to be parallel. In other words, an outer surface of the second member located at a position that allows the aforementioned convex portion to be formed on the joining surface can be appropriately selected as the "laser irradiated surface". Therefore, the "laser irradiated surface" of the second member may be an outer surface in the normal direction as viewed from the joining surface (first or second embodiment), or an outer surface in a direction inclined from the normal direction (third embodiment).

[0149] Therefore, the outer surface of the second member that is to be irradiated with the laser may be located in the normal direction of the joining surface or in a direction inclined from the normal direction (inclination direction). Here, the angle (inclination angle) θ between the inclination direction and the normal direction is not particularly limited, and for example, when the normal direction is set as the reference 0°, it may be theoretically within a range of more than 0° and less than 180° (0°<θ<180°).

[0150] An example of a preferable inclination angle θ is in the range of more than 0° and not more than 90° (0°<θ≦90°). If the inclination angle θ is within this range, the angle between the joining surface (fixing surface) and the outer surface (laser irradiated surface) becomes a right angle or an acute angle, so that the distance between the joining surface and the outer surface (the thickness of the second member (base material) located between the fixing surface and the laser irradiated surface) can be made relatively small.

[0151] In addition, in the method for joining iron-based members according to the present disclosure, the configuration of the convex portion and the concave portion, i.e., the configuration of the fixing portion, the specific configurations of the first member and the second member, and the conditions such as the laser irradiation conditions are not particularly limited. As for these configurations or conditions, the configurations or conditions described in the above-mentioned first to third embodiments can be suitably used.

[0152] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims. The technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in different embodiments or multiple modified examples.

[0153] From the above description, many improvements and other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the above description should be construed as merely illustrative and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. Details of the structure and / or function thereof may be substantially changed without departing from the spirit of the present invention. [Industrial Applicability]

[0154] As described above, according to the present invention, the first and second members of the compressor can be firmly fixed with a simple configuration, so that the reliability of the compressor can be improved and the size can be reduced. Therefore, the present invention can be widely applied to various devices using a refrigeration cycle. [Explanation of symbols]

[0155] 100A~100C: Compressor 102: Airtight container 104,105: Electric element 106: Compression element 120: Crankshaft 122: Eccentric shaft 124: Main shaft 126: Sliding surface 127: Non-sliding surface 128: Flange 130: Cylinder block 140: Piston 142: Connection means 150,157: Stator 152, 158: Rotor 153: Frame 156: Rotor shaft hole 160: Core 162: Coil 164: Insulating material 171, 172: Balance weight 180: Lubricating oil 181: Refrigerant gas 200A~200C: Fixed part 210: First member 220: Second member 211, 213, 215: Convex 212, 214, 216: Laser irradiation marks 221, 223, 225: Recesses 230: Gap

Claims

1. A first member and a second member fixed to the first member, the first member and the second member are made of an iron-based material that is iron or an iron alloy, and the iron-based material constituting the first member has a higher carbon content than the iron-based material constituting the second member; a fixed surface of the first member that is to be fixed to the second member is in contact with a fixing surface of the second member, the second member has a protrusion formed on the fixing surface by laser processing and protruding relative to the fixed surface of the first member; the first member has a recess in the fixed surface that closely fits into the protrusion, the convex portion is a laser-irradiated deformed portion that is directly generated by laser irradiation of the second member and is made only of the iron-based material of the second member, The distance between the fixing surface and the laser irradiation surface, which is the opposing surface of the convex portion, is 0.5 mm or more. Compressor.

2. When a surface of the second member located on the opposite side to a protruding direction of the protruding portion is defined as a protruding portion facing surface, a laser irradiation mark is formed on the convex portion facing surface of the second member at a position facing the convex portion on the fixing surface through a main body of the second member, The compressor according to claim 1.

3. The compressor includes an electric element including at least a stator and a rotor, and a compression element driven by the electric element; The compression element includes a crankshaft that is a shaft portion, the first member is the crankshaft, and the second member is a balance weight fixed to the crankshaft, or a support portion of the rotor fixed to the crankshaft, The compressor according to claim 1 or 2.

4. The rotation speed of the crankshaft is 60 rps or more. The compressor according to claim 3.

5. A refrigerant circuit including the compressor according to any one of claims 1 to 4, a radiator, a pressure reducing device, and a heat sink, and connecting these in a ring shape by piping. Refrigeration and freezing equipment.

6. When fixing the first member and the second member of the compressor, the first member is made of an iron-based material that is iron or an iron alloy, and the second member is made of an iron-based material having a lower carbon content than the iron-based material constituting the first member; a fixing surface of the second member is brought into contact with a fixed surface of the first member that is to be fixed to the second member; A laser having a laser output of 5000 W or less is irradiated from an outer surface of the second member, the outer surface being located in a normal direction to the fixing surface of the second member or in a direction inclined from the normal direction, toward the fixing surface, A convex portion is formed on the fixing surface of the second member, the convex portion being a laser irradiation deformed portion that is directly generated by laser irradiation of the second member and is made only of the iron-based material of the second member and that protrudes toward the fixed surface of the first member, The fixed surface of the first member is formed with a recess in association with the formation of the protrusion. A method for manufacturing a compressor.

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