Rotary compressor and vane manufacturing method

Abstract

This suppresses the reduction in sealing performance between the vane and the piston. [Solution] The vane manufacturing method is a method for manufacturing a vane 127 used in a rotary compressor, and includes a step (S5) of coating the tip surface 129a, the first end surface 129d, and the second end surface 129e with a tip surface high hardness coating layer 220, the first end surface high hardness coating layer 231, and the second end surface high hardness coating layer 232, respectively, and a step (S6) of nitriding the base material layer 210 after the step (S5) of coating the tip surface 129a, the first end surface 129d, and the second end surface 129e has been performed, so that the first side surface 129b and the second side surface 129c are coated with a first side surface nitride layer 221 and the second side surface nitride layer 222, respectively.

Description

Technical Field

[0001] The present invention relates to a rotary compressor and a method for manufacturing a vane.

Background Art

[0002] A rotary compressor including a cylinder, a piston that revolves along the inner peripheral surface of the cylinder, an end plate that closes the end of the cylinder, and a vane that divides the cylinder chamber surrounded by the cylinder, the piston, and the end plate into a suction chamber and a compression chamber is known (Patent Documents 1 and 2). In such a rotary compressor, the vane is nitrided, improving its wear resistance and seizure resistance.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the vane is nitrided, a nitride layer is formed on the surface of the vane. The nitride layer is formed by nitrogen penetrating into the material forming the vane (for example, stainless steel). Therefore, when the end face is covered by the nitride layer, the volume of the portion of the vane where the nitride layer is formed increases, and protrusions may be formed in the region near the end of the tip face. In the rotary compressor, due to the protrusions formed in the region near the end of the tip face, the clearance formed between the vane and the piston becomes larger, reducing the sealing performance between the vane and the piston and causing a problem of reduced compression performance.

[0005] The disclosed technology has been made in view of the foregoing and aims to provide a rotary compressor and a method for manufacturing vanes that suppresses a decrease in the sealing performance between the vanes and the piston. [Means for solving the problem]

[0006] A rotary compressor according to one aspect of the present disclosure comprises a cylinder, a piston that revolves along the inner circumferential surface of the cylinder, end plates that close both ends of the cylinder, and vanes that divide a cylinder chamber surrounded by the cylinder, the piston, and the end plates into an intake chamber and a compression chamber, wherein the vanes have a base material layer made of a base material, a high-hardness coating layer covering the tip surface of the base material layer that slides against the outer circumferential surface of the piston, and a nitrided layer covering the side surface of the base material layer that slides against the inner surface of the vane groove of the cylinder, wherein the end surface of the base material layer that slides against the end plates is not covered by the nitrided layer. [Effects of the Invention]

[0007] The rotary compressor and vane manufacturing method of this disclosure can suppress a decrease in sealing performance between the vane and the piston. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a longitudinal cross-sectional view showing the rotary compressor of Example 1. [Figure 2] Figure 2 is an exploded perspective view showing the compression section of the rotary compressor of Example 1. [Figure 3] Figure 3 is a perspective view showing the vanes of the rotary compressor in Example 1. [Figure 4] Figure 4 is a cross-sectional view showing the tip surface, first side surface, and second side surface of the vane. [Figure 5] Figure 5 is a cross-sectional view showing the tip surface, first end surface, and second end surface of the vane. [Figure 6] Figure 6 is a schematic diagram illustrating the manufacturing method of the vane in Example 1. [Figure 7]Figure 7 is a schematic diagram illustrating the vane manufacturing method of a comparative example. [Figure 8] Figure 8 is a graph showing the results of shape measurement of the tip surface of the vane of the comparative example. [Figure 9] Figure 9 is a perspective view showing multiple coated vanes in the vane manufacturing method of Example 2. [Modes for carrying out the invention]

[0009] The following describes the manufacturing method of the rotary compressor and vanes according to the embodiments disclosed herein, with reference to the drawings. However, the following description does not limit the technology of this disclosure. Furthermore, the same reference numerals are used for identical components, and redundant explanations are omitted. [Examples]

[0010] (Compressor configuration) Figure 1 is a longitudinal cross-sectional view showing the rotary compressor 1 of Embodiment 1. As shown in Figure 1, the rotary compressor 1 houses a compression unit 12 that draws in refrigerant from an accumulator 25 and discharges the compressed refrigerant into the main body container 10, and a motor 11 that drives the compression unit 12. The high-pressure refrigerant compressed by the compression unit 12 is discharged into the main body container 10 and further discharged to the refrigeration cycle through a discharge pipe 107. The rotary compressor 1 also includes a rotating shaft 15 that transmits the driving force of the motor 11 to the compression unit 12, and an accumulator 25 fixed to the outer circumferential surface of the main body container 10.

[0011] The main container 10 is provided with an upper compression suction pipe 102T and a lower compression suction pipe 102S that pass through the main container 10 for drawing low-pressure refrigerant from the refrigeration cycle into the compression section 12. Specifically, the upper guide pipe 101T is fixed to the main container 10, for example by brazing, and the upper compression suction pipe 102T passes inside the upper guide pipe 101T and is fixed to the upper guide pipe 101T, for example by brazing. Similarly, the lower guide pipe 101S is fixed to the main container 10, for example by brazing, and the lower compression suction pipe 102S passes inside the lower guide pipe 101S and is fixed to the lower guide pipe 101S, for example by brazing.

[0012] A discharge pipe 107 is provided, penetrating the upper part of the main container 10, for discharging the high-pressure refrigerant compressed in the compression section 12 from inside the main container 10 into the refrigeration cycle. A base member 310, which supports the entire rotary compressor 1, is fixed to the lower part of the main container 10 by welding.

[0013] The accumulator 25 includes an accumulator suction pipe 27 for drawing refrigerant from the refrigeration cycle into the accumulator 25, and an upper gas-liquid separation pipe 31T and a lower gas-liquid separation pipe 31S for sending gaseous refrigerant to the compression section 12. The accumulator suction pipe 27 is connected to the upper part of the accumulator 25. The upper gas-liquid separation pipe 31T is connected to the upper compression section suction pipe 102T via an upper connecting pipe 104T. The lower gas-liquid separation pipe 31S is connected to the lower compression section suction pipe 102S via a lower connecting pipe 104S.

[0014] FIG. 2 is an exploded perspective view showing the compression section 12 of the rotary compressor 1 of Example 1. As shown in FIGS. 1 and 2, the compression section 12 has an upper cylinder 121T, a lower cylinder 121S, an intermediate partition plate 140, an upper end plate 160T, and a lower end plate 160S. The upper end plate 160T, the upper cylinder 121T, the intermediate partition plate 140, the lower cylinder 121S, and the lower end plate 160S are stacked in this order and fixed by a plurality of bolts 175. A main bearing portion 161T is provided on the upper end plate 160T. A sub-bearing portion 161S is provided on the lower end plate 160S. The rotating shaft 15 is provided with a main shaft portion 153, an upper eccentric portion 152T, a lower eccentric portion 152S, and a sub-shaft portion 151. The rotating shaft 15 has a main shaft portion 153 and a sub-shaft portion 151 supported by the compression section 12. The main shaft portion 153 of the rotating shaft 15 is fitted into the main bearing portion 161T of the upper end plate 160T, and the sub-shaft portion 151 of the rotating shaft 15 is fitted into the sub-bearing portion 161S of the lower end plate 160S, whereby the rotating shaft 15 is rotatably supported by the main bearing portion 161T and the sub-bearing portion 161S.

[0015] The motor 11 has a stator 111 disposed on the outside and a rotor 112 disposed on the inside. The stator 111 is fixed to the inner peripheral surface 10a of the main body container 10, for example, by shrink fitting or welding. The rotor 112 is fixed to the rotating shaft 15 by shrink fitting.

[0016] Inside the main body container 10, lubricating oil 18 in an amount such that the compression section 12 is substantially immersed is enclosed for lubrication of the sliding members of the compression section 12 and for sealing between the high-pressure portion and the low-pressure portion in the cylinder chamber.

[0017] Next, the compression unit 12 will be described in detail with reference to FIG. 2. The upper cylinder 121T is formed in an annular shape. An upper hollow portion 130T having a cylindrical shape is provided inside the upper cylinder 121T, and an upper piston 125T is disposed in the upper hollow portion 130T. The upper piston 125T is fitted into the upper eccentric portion 152T of the rotating shaft 15 (FIG. 1). The lower cylinder 121S is formed in an annular shape. A lower hollow portion 130S having a cylindrical shape is provided inside the lower cylinder 121S, and a lower piston 125S is disposed in the lower hollow portion 130S. The lower piston 125S is fitted into the lower eccentric portion 152S of the rotating shaft 15.

[0018] The upper cylinder 121T is provided with an upper vane groove 128T extending from the upper hollow portion 130T to the outer peripheral side, and an upper vane 127T is disposed in the upper vane groove 128T. The upper cylinder 121T is provided with an upper spring hole 124T communicating from the outer periphery to the upper vane groove 128T, and an upper spring 126T is disposed in the upper spring hole 124T. The lower cylinder 121S is provided with a lower vane groove 128S extending from the lower hollow portion 130S to the outer peripheral side, and a lower vane 127S is disposed in the lower vane groove 128S. The lower cylinder 121S is provided with a lower spring hole 124S communicating from the outer periphery to the lower vane groove 128S, and a lower spring 126S is disposed in the lower spring hole 124S.

[0019] One end of the upper vane 127T is pressed against the upper piston 125T by the upper spring 126T, thereby dividing the upper cylinder chamber, which is the space outside the upper piston 125T in the upper hollow portion 130T of the upper cylinder 121T, into an upper intake chamber 131T and an upper compression chamber 133T. The upper cylinder 121T is provided with an upper intake hole 135T that communicates with the upper intake chamber 131T from the outer circumference. The upper compression intake pipe 102T is connected to the upper intake hole 135T. One end of the lower vane 127S is pressed against the lower piston 125S by the lower spring 126S, thereby dividing the lower cylinder chamber, which is the space outside the lower piston 125S in the lower hollow portion 130S of the lower cylinder 121S, into a lower intake chamber 131S and a lower compression chamber 133S. The lower cylinder 121S is provided with a lower intake hole 135S that communicates with the lower intake chamber 131S from the outer circumference. The lower intake port 135S is connected to the lower compression intake pipe 102S.

[0020] The upper end plate 160T is provided with an upper discharge hole 190T that penetrates the upper end plate 160T and communicates with the upper compression chamber 133T. An upper discharge valve 200T, which is a reed valve that opens and closes the upper discharge hole 190T, and an upper discharge valve retainer 201T that restricts the warping of the upper discharge valve 200T are fixed to the upper end plate 160T by upper rivets 202T. An upper end plate cover 170T is positioned above the upper end plate 160T, covering the upper discharge hole 190T, and an upper end plate cover chamber 180T is formed, which is closed by the upper end plate 160T and the upper end plate cover 170T. The upper end plate cover 170T is fixed to the upper end plate 160T by a plurality of bolts 175 that fix the upper end plate 160T and the upper cylinder 121T. The upper end plate cover 170T is provided with an upper end plate cover discharge hole 172T that connects the upper end plate cover chamber 180T to the inside of the main container 10. Furthermore, when the compression section 12 is installed inside the main container 10, the inner circumferential surface 10a of the main container 10 is shrink-fitted to the outer circumferential surface 182a of the upper end plate 160T, and is joined to the main container 10 by multiple welds.

[0021] The lower end plate 160S is provided with a lower discharge hole 190S that penetrates the lower end plate 160S and communicates with the lower compression chamber 133S. A lower discharge valve 200S, which is a reed valve that opens and closes the lower discharge hole 190S, and a lower discharge valve retainer 201S that restricts the warping of the lower discharge valve 200S are fixed to the lower end plate 160S by lower rivets 202S. A lower end plate cover 170S is positioned below the lower end plate 160S, covering the lower discharge hole 190S, and the lower end plate 160S and the lower end plate cover 170S form a lower end plate cover chamber 180S that is closed off (see Figure 1). The lower end plate cover 170S is fixed to the lower end plate 160S by a plurality of bolts 175 that fix the lower end plate 160S and the lower cylinder 121S.

[0022] Furthermore, the compression section 12 is provided with a refrigerant passage hole 136 (see Figure 2) that penetrates the lower end plate 160S, the lower cylinder 121S, the intermediate partition plate 140, the upper end plate 160T, and the upper cylinder 121T, and connects the lower end plate cover chamber 180S and the upper end plate cover chamber 180T.

[0023] The following describes the flow of refrigerant due to the rotation of the rotating shaft 15. As the rotating shaft 15 rotates, the upper piston 125T fitted into the upper eccentric part 152T of the rotating shaft 15 and the lower piston 125S fitted into the lower eccentric part 152S revolve, causing the upper intake chamber 131T and the lower intake chamber 131S to expand in volume and draw in refrigerant. As the refrigerant intake path, the low-pressure refrigerant of the refrigeration cycle is drawn into the accumulator 25 through the accumulator intake pipe 27, and only gaseous refrigerant is drawn into the upper gas-liquid separation pipe 31T and the lower gas-liquid separation pipe 31S. The gaseous refrigerant drawn into the upper gas-liquid separation pipe 31T is drawn into the upper intake chamber 131T through the upper connecting pipe 104T and the upper compression section intake pipe 102T. Similarly, the gaseous refrigerant drawn into the lower gas-liquid separation pipe 31S is drawn into the lower suction chamber 131S through the lower connecting pipe 104S and the lower compression section suction pipe 102S.

[0024] Next, the flow of the discharged refrigerant due to the rotation of the rotating shaft 15 will be explained. As the rotating shaft 15 rotates, the upper piston 125T fitted to the upper eccentric portion 152T of the rotating shaft 15 revolves, compressing the refrigerant while reducing the volume of the upper compression chamber 133T. When the pressure of the compressed refrigerant becomes higher than the pressure in the upper end plate cover chamber 180T outside the upper discharge valve 200T, the upper discharge valve 200T opens and discharges the refrigerant from the upper compression chamber 133T to the upper end plate cover chamber 180T. The refrigerant discharged into the upper end plate cover chamber 180T is discharged into the main container 10 through the upper end plate cover discharge hole 172T provided in the upper end plate cover 170T.

[0025] Furthermore, the rotation of the rotating shaft 15 causes the lower piston 125S, fitted into the lower eccentric portion 152S of the rotating shaft 15, to revolve, compressing the refrigerant while reducing the volume of the lower compression chamber 133S. When the pressure of the compressed refrigerant becomes higher than the pressure in the lower end plate cover chamber 180S outside the lower discharge valve 200S, the lower discharge valve 200S opens and discharges the refrigerant from the lower compression chamber 133S to the lower end plate cover chamber 180S. The refrigerant discharged into the lower end plate cover chamber 180S passes through the refrigerant passage hole 136 and the upper end plate cover chamber 180T and is discharged into the main container 10 from the upper end plate cover discharge hole 172T provided in the upper end plate cover 170T.

[0026] The refrigerant discharged into the main container 10 is guided to the top of the motor 11 through a notch (not shown) connecting the top and bottom on the outer circumference of the stator 111, or a gap (not shown) in the winding portion of the stator 111, or a gap 115 (see Figure 1) between the stator 111 and the rotor 112, and is discharged from a discharge pipe 107 located at the top of the main container 10.

[0027] Next, the flow of the lubricating oil 18 will be explained. The lubricating oil 18 sealed in the lower part of the main container 10 is supplied to the compression section 12 by the centrifugal force of the rotating shaft 15, passing through the inside of the rotating shaft 15 (not shown). The lubricating oil 18 supplied to the compression section 12 is drawn into the refrigerant, becomes atomized, and is discharged into the main container 10 together with the refrigerant. The lubricating oil 18 that has been discharged into the main container 10 as atomization is separated from the refrigerant by centrifugal force due to the rotational force of the motor 11, and returns to the lower part of the main container 10 as oil droplets. However, some of the lubricating oil 18 is not separated and is discharged into the refrigeration cycle together with the refrigerant. The lubricating oil 18 discharged into the refrigeration cycle circulates through the refrigeration cycle and returns to the accumulator 25, where it is separated and remains in the lower part of the accumulator 25. The lubricating oil 18 remaining in the lower part of the accumulator 25 is drawn into the upper intake chamber 131T and the lower intake chamber 131S together with the intake refrigerant.

[0028] (Characteristic configuration of rotary compressor 1) Next, the characteristic configuration of the rotary compressor 1 of Embodiment 1 will be described. Figure 3 is a perspective view showing the vane 127 of the rotary compressor 1 of Embodiment 1. Since the upper vane 127T and the lower vane 127S (hereinafter also referred to as vane 127) have the same structure, the upper vane 127T will be described below, and the description of the lower vane 127S will be omitted. The upper vane 127T has a tip surface 129a that slides against the outer circumferential surface of the upper piston 125T, and a first side surface 129b and a second side surface 129c that slide against the inner surface of the upper vane groove 128T. The upper vane 127T also has a first end surface 129d that slides against the end surface of the upper end plate 160T, a second end surface 129e that slides against the end surface of the intermediate partition plate 140 which serves as an end plate, and a back surface 129f that is pressed by the upper spring 126T. To elaborate on the lower vane 127S, it has a first side surface 129b and a second side surface 129c that slide against the inner surface of the lower vane groove 128S, a first end surface 129d that slides against the end surface of the intermediate partition plate 140 which serves as an end plate, and a second end surface 129e that slides against the end surface of the lower end plate 160S. The first side surface 129b and the second side surface 129c, and the first end surface 129d and the second end surface 129e are each formed flat.

[0029] The tip surface 129a of the upper vane 127T is formed in an arc shape when viewed from a direction perpendicular to the first end surface 129d and the second end surface 129e. On the back surface 129f of the upper vane 127T, an engaging portion 138 is formed by cutting out a part of the flat back surface 129f, into which the end of the upper spring 126T engages. The end of the lower spring 126S engages with the engaging portion 138 of the lower vane 127S.

[0030] As shown in Figure 4, the vane 127 comprises a base material layer 210, a tip surface high-hardness coating layer 220, a first side surface nitride layer 221, and a second side surface nitride layer 222. Figure 4 is a cross-sectional view showing the tip surface 129a, the first side surface 129b, and the second side surface 129c of the vane 127. Figure 4 shows a cross-section of the vane 127 cut by a plane parallel to the first end surface 129d or the second end surface 129e of the vane 127. The base material layer 210 is formed of a material with a chromium Cr content exceeding 4.5 wt%. Examples of materials used include SUS440C (a type of martensitic stainless steel) with a chromium content of approximately 16 wt% to 18 wt%, SKD61 (a type of die steel) with a chromium content of approximately 4.8 wt% to 5.5 wt%, and SKD11 (a type of die steel) with a chromium content of approximately 11.0 wt% to 13.0 wt%. In this way, the vane 127 ensures appropriate wear resistance and seizure resistance by forming the base layer 210 with a material having a chromium content exceeding 4.5 wt%. Furthermore, when the vane 127 is formed with stainless steel having a chromium content exceeding 10 wt%, sufficient wear resistance and seizure resistance can be ensured, especially for the first side surface 129b and the second side surface 129c, which have a large sliding surface area.

[0031] The tip surface 129a of the vane 127 is covered with a tip surface high-hardness coating layer 220 so that the base material layer 210 is not exposed at the tip surface 129a. The tip surface high-hardness coating layer 220 is formed from a material with a Vickers hardness of 1500 HV or higher. Examples of such materials include diamond-like carbon (DLC), chromium nitride (CrN), and dichrome nitride (Cr2N).

[0032] The first side surface 129b of the vane 127 is covered by a first side nitride layer 221 so that the base material layer 210 is not exposed on the first side surface 129b. The first side nitride layer 221 is formed by the penetration of nitrogen atoms N into the material on which the base material layer 210 is formed. Examples of such nitride layers include a nitride diffusion layer in which nitrogen atoms N are solid-dissolved in the material on which the base material layer 210 is formed, forming a body-centered cubic α (alpha) phase, and a dense layer in which iron nitride Fe4N is the main component and forms a face-centered cubic γ' (gamma prime) phase. The second side surface 129c of the vane 127 is covered by a second side nitride layer 222 so that the base material layer 210 is not exposed on the second side surface 129c. The second side nitride layer 222 is formed in the same manner as the first side nitride layer 221.

[0033] Figure 5 is a cross-sectional view showing the leading edge 129a, the first end face 129d, and the second end face 129e of the vane 127. Figure 5 shows a cross-section of the vane 127 cut by a plane parallel to the first side surface 129b or the second side surface 129c of the vane 127. The vane 127 further comprises a first end face high hardness coating layer 231 and a second end face high hardness coating layer 232. The first end face 129d of the vane 127 is covered by the first end face high hardness coating layer 231 so that the base material layer 210 is not exposed at the first end face 129d. The second end face 129e of the vane 127 is covered by the second end face high hardness coating layer 232 so that the base material layer 210 is not exposed at the second end face 129e. The first end face high hardness coating layer 231 and the second end face high hardness coating layer 232 are formed from the same material as the material on which the tip surface high hardness coating layer 220 is formed.

[0034] The vane 127 has a tip surface 129a that is covered with a tip surface high-hardness coating layer 220, thereby ensuring adequate wear resistance of the tip surface 129a so that it does not wear down when the rotary compressor 1 compresses the refrigerant. Furthermore, the vane 127 has a first side surface 129b and a second side surface 129c that are covered with a first side surface nitride layer 221 and a second side surface nitride layer 222, respectively, thereby ensuring adequate wear resistance of the first side surface 129b and the second side surface 129c so that they do not wear down when the rotary compressor 1 compresses the refrigerant. In addition, since the tip surface 129a is particularly susceptible to wear, it is desirable to ensure wear resistance by a high-hardness coating rather than nitriding treatment.

[0035] (Method for manufacturing the vane in Example 1) Here, the manufacturing method of the vane in Example 1 will be described. The manufacturing method of the vane in Example 1 is the same as the method for manufacturing the vane 127 described above. The following description is an example of the manufacturing process. Figure 6 is a schematic diagram illustrating the manufacturing method of the vane in Example 1. First, a plate 301, which is the material for forming the base material layer 210, is prepared. The plate 301 is cut into the approximate shape of the vane 127 (step S1), and a post-cut vane 302 is formed. A first side surface 129b, a second side surface 129c, and a back surface 129f are formed on the post-cut vane 302, an engaging portion 138 is formed, and the base material layer 210 is formed.

[0036] After cutting, the vane 302 is ground (step S2) to form a vane 303 with a first end face 129d and a second end face 129e. The vane 303 with a rough end face is further ground (step S3) to form a vane 304 with a tip R-face ground, where a tip surface 129a is formed. The vane 304 with a tip R-face ground is further ground (step S4) to form a vane 305 with a fine end face.

[0037] The multiple end-face polished vanes 305 formed as described above are arranged such that the first side surface 129b of one end-face polished vane 305 is in close contact with the second side surface 129c of another end-face polished vane, and the second side surface 129c of the end-face polished vane 305 is in close contact with the first side surface 129b of yet another end-face polished vane. With the multiple end-face polished vanes arranged, the multiple end-face polished vanes are subjected to CVD (chemical vapor deposition) or PVD (physical vapor deposition) (step S5). As a result of the CVD or PVD method being applied to the multiple end-face polished vanes, the tip surface 129a, the first end surface 129d, and the second end surface 129e are covered with a high-hardness coating layer, forming a coated vane 306. Specifically, the leading edge surface 129a of the coated vane 306 is covered with a leading edge high-hardness coating layer 220, the first end surface 129d is covered with a first end surface high-hardness coating layer 231, and the second end surface 129e is covered with a second end surface high-hardness coating layer 232. The first side surface 129b and the second side surface 129c of the coated vane 306 are not covered with the high-hardness coating layer because the CVD or PVD method is performed with multiple end-face polished vanes arranged side by side, and the base material layer 210 is exposed.

[0038] The coated vane 306 is subjected to nitriding treatment (step S6) to form the nitrided vane 307. Examples of nitriding treatments include gas nitriding, gas soft nitriding, and ion nitriding. In the nitriding treatment, nitrogen atoms N do not penetrate into the base material layer 210 from the tip surface 129a, the first end surface 129d, and the second end surface 129e of the coated vane 306, which are covered by the high-hardness coating layer. In the nitriding treatment, nitrogen atoms N penetrate into the base material layer 210 from the first side surface 129b and the second side surface 129c of the coated vane 306, which are not covered by the high-hardness coating layer, and the nitrogen atoms N diffuse into the base material layer 210. As nitrogen atoms N diffuse into the base material layer 210, a first side nitride layer 221 is formed in the region near the first side surface 129b of the base material layer 210, and a second side nitride layer 222 is formed in the region near the second side surface 129c of the base material layer 210. That is, after nitriding, the first side surface 129b of the vane 307 is covered by the first side nitride layer 221, and the second side surface 129c is covered by the second side nitride layer 222.

[0039] After nitriding, the vane 307 is formed by grinding the first end face 129d and the second end face 129e to adjust their height (step S7). The vane 127 is formed such that the distance between the first end face 129d and the second end face 129e is equal to a predetermined height as a result of the height adjustment in step S7. The vane 127 is further formed such that the first end face 129d is perpendicular to the tip face 129a, and the second end face 129e is perpendicular to the tip face 129a as a result of the height adjustment in step S7.

[0040] According to this method of manufacturing vanes, the vanes 127 are manufactured appropriately so that no protrusions are formed on the tip surface 129a. The rotary compressor 1 can prevent improper clearance between the upper vane 127T and the upper piston 125T because no protrusions are formed on the tip surface 129a of the vanes 127.

[0041] [Comparative example vane manufacturing method] The vane manufacturing method of the comparative example, as shown in Figure 7, includes the same steps S1 to S4 as the vane manufacturing method of Example 1 described above, but the steps from step S5 onwards of the vane manufacturing method of Example 1 described above are replaced with other steps. Figure 7 is a schematic diagram illustrating the vane manufacturing method of the comparative example. In the vane manufacturing method of the comparative example, the vane 305 after end-face grinding is formed by performing the steps S1 to S4, similar to the vane manufacturing method of Example 1 described above.

[0042] Multiple end-face polished vanes, including the end-face polished vane 305, are arranged so that the first side surface 129b and the second side surface 129c are in close contact, and the first end surface 129d and the second end surface 129e are in close contact. With the multiple end-face polished vanes arranged, the multiple end-face polished vanes are subjected to a CVD method or a PVD method (step S101). As a result of the CVD method or PVD method being performed on the multiple end-face polished vanes, the tip surface 129a of the end-face polished vane 305 is covered with a high-hardness coating layer 312, forming a coated vane 311. That is, the tip surface 129a of the coated vane 311 is covered with a high-hardness coating layer 312. The first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e of the coated vane 306 are not covered by the high-hardness coating layer, and the base material layer 210 is exposed, because the CVD or PVD method is performed with multiple end-face-ground vanes arranged side by side.

[0043] After coating, the vane 311 is subjected to nitriding (step S102) to form the comparative example vane 313. During the nitriding process, nitrogen atoms N penetrate into the base material layer 210 from the first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e of the surface of the vane 311 that are not covered by the high-hardness coating layer 312, and diffuse into the base material layer 210. As nitrogen atoms N diffuse into the base material layer 210, a nitrided layer is formed in the vicinity of the first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e of the base material layer 210. In other words, the first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e of the comparative example vane 313 are covered with a nitride layer so that the base material layer 210 is not exposed at the first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e.

[0044] The regions of the base material layer 210 near the first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e expand due to the diffusion of nitrogen atoms N. A protrusion is formed at the first end 316 on the side of the first end surface 129d of the tip surface 129a of the comparative example vane 313 due to the expansion of the region of the base material layer 210 near the first end surface 129d. A protrusion is formed at the second end 317 on the side of the second end surface 129e of the tip surface 129a of the comparative example vane 313 due to the expansion of the region of the base material layer 210 near the second end surface 129e. Figure 8 is a graph showing the results of shape measurement of the tip surface 129a of the comparative example vane 313. The graph in Figure 8 shows that a protrusion is formed at the first end 316 and at the second end 317. In other words, the tip surface 129a of the comparative example vane 313 has protrusions formed at both ends (first end 316, second end 317) in the longitudinal direction of the tip surface 129a.

[0045] When the vane 313 of the comparative example is used as the upper vane 127T of the rotary compressor 1, the presence of protrusions at the first end 316 and the second end 317 results in an improper clearance between the vane 313 of the comparative example and the upper piston 125T. The sealing performance between the vane 313 of the comparative example and the upper piston 125T is reduced when the clearance is improper.

[0046] In contrast, the rotary compressor 1 of Example 1 can prevent the formation of protrusions on both ends of the longitudinal direction of the tip surface 129a of the vane 127, thereby enabling the formation of an appropriate clearance. That is, the rotary compressor 1 of Example 1 described above can suppress the decrease in sealing performance between the upper vane 127T and the upper piston 125T, and can suppress the decrease in sealing performance between the lower vane 127S and the lower piston 125S, compared to the other rotary compressors equipped with the vane 313 of the comparative example.

[0047] [Effects of the vane manufacturing method in Example 1] The vane manufacturing method of Example 1 is a method for manufacturing vanes 127 used in a rotary compressor 1. Step S5 involves coating the tip surface 129a, the first end surface 129d, and the second end surface 129e with a tip surface high-hardness coating layer 220, a first end surface high-hardness coating layer 231, and a second end surface high-hardness coating layer 232, respectively. After the step of coating the tip surface 129a, the first end surface 129d, and the second end surface 129e (step S5) is performed, the base material layer 210 is nitrided so that the first side surface 129b and the second side surface 129c are coated by the first side surface nitride layer 221 and the second side surface nitride layer 222, respectively (step S6). It includes and.

[0048] The vane manufacturing method of Example 1 can prevent nitrogen atoms N from diffusing into the region near the first end face 129d and the second end face 129e of the base material layer 210 during the nitriding treatment. Therefore, the vane manufacturing method of Example 1 can prevent the region near the first end face 129d and the second end face 129e of the base material layer 210 from expanding, and can suppress the formation of protrusions on the first end 316 and the second end 317 of the tip surface 129a.

[0049] The rotary compressor 1 of Embodiment 1 comprises an upper cylinder 121T, an upper piston 125T, an upper end plate 160T, an intermediate partition plate 140, and an upper vane 127T. The upper piston 125T revolves along the inner circumferential surface of the upper cylinder 121T. The upper end plate 160T and the intermediate partition plate 140 close both ends of the upper cylinder 121T. The upper vane 127T divides the upper cylinder chamber, which is surrounded by the upper cylinder 121T, the upper piston 125T, the upper end plate 160T, and the intermediate partition plate 140, into an upper intake chamber 131T and an upper compression chamber 133T. The upper vane 127T comprises a base material layer 210, a tip surface high-hardness coating layer 220, a first side nitride layer 221, and a second side nitride layer 222. The base material layer 210 is made of the base material. The tip surface high-hardness coating layer 220 covers the tip surface 129a of the base material layer 210 that slides against the outer circumferential surface of the upper piston 125T. The first side nitride layer 221 and the second side nitride layer 222 cover the first side surface 129b and the second side surface 129c of the base material layer 210 that slide against the inner surface of the upper vane groove 128T of the upper cylinder 121T, respectively. The upper vane 127T is formed such that the first end surface 129d and the second end surface 129e of the base material layer 210 that slide against the upper end plate 160T and the intermediate partition plate 140 are not covered by the nitride layer.

[0050] In this case, the rotary compressor 1 of Example 1 is prevented from expanding the region near the first end face 129d and the second end face 129e of the base material layer 210 during the nitriding treatment, and the formation of protrusions on the first end 316 and the second end 317 of the tip surface 129a can be prevented. By preventing the formation of protrusions on the first end 316 and the second end 317 of the rotary compressor 1 of Example 1, the clearance formed between the upper vane 127T and the upper piston 125T can be prevented from becoming improper. Therefore, the rotary compressor 1 of Example 1 can suppress a decrease in sealing performance between the upper vane 127T and the upper piston 125T, and thus can suppress a decrease in compression performance.

[0051] Furthermore, the upper vane 127T of the rotary compressor 1 of Example 1 is further provided with a first end face high hardness coating layer 231 and a second end face high hardness coating layer 232 that cover the first end face 129d and the second end face 129e, respectively. In this case, the rotary compressor 1 of Example 1 can prevent nitrogen atoms from penetrating the region of the base material layer 210 near the first end face 129d and the second end face 129e during nitriding treatment, and can prevent the region of the base material layer 210 near the first end face 129d and the second end face 129e from expanding.

[0052] By the way, in Example 1, the first end face 129d and the second end face 129e of the vane 127 are covered by the first end face high hardness coating layer 231 and the second end face high hardness coating layer 232, respectively, but the base material layer 210 may be exposed at the first end face 129d and the second end face 129e. For example, after nitriding treatment, the first end face high hardness coating layer 231 and the second end face high hardness coating layer 232 may be removed by the height adjustment in step S7. Even when the base material layer 210 is exposed at the first end face 129d and the second end face 129e, the vane 127 can be used appropriately in the rotary compressor 1 because the wear resistance and seizure resistance of the base material layer 210 are adequately ensured. [Examples]

[0053] The vane manufacturing method of Example 2 includes the same steps S1 to S4 as the vane manufacturing method of Example 1 described above, but steps S5 to S7 of the vane manufacturing method of Example 1 described above are replaced with other processes. Multiple end-face polished vanes, including the end-face polished vane 305 formed by the steps S1 to S4, are arranged so that the first side surface 129b and the second side surface 129c are in close contact, and the first end surface 129d and the second end surface 129e are in close contact. With the multiple end-face polished vanes arranged, the multiple end-face polished vanes are subjected to a CVD method or a PVD method, similar to the step S5 process described above. By performing the CVD method or PVD method on the multiple end-face polished vanes, the leading edge 129a of each of the multiple end-face polished vanes is covered with a high-hardness coating layer, and multiple coated vanes are formed. The first side surface 129b, second side surface 129c, first end surface 129d, and second end surface 129e of each of the multiple post-coated vanes are not covered by the high-hardness coating layer, and the base material layer 210 is exposed, because the CVD or PVD method is performed on the multiple post-finishing vanes in a line.

[0054] The multiple post-coated vanes 401 are arranged so that their first end faces 129d and second end faces 129e are in close contact, as shown in Figure 9. Figure 9 is a perspective view showing the multiple post-coated vanes 401 in the vane manufacturing method of Example 2. With the multiple post-coated vanes 401 arranged, they are subjected to nitriding treatment, and their first side surface 129b and second side surface 129c are covered with a nitrided layer, forming multiple nitrided vanes. The first end face 129d and second end face 129e of each of the multiple nitrided vanes are not covered with the nitrided layer because they were subjected to nitriding treatment while the multiple post-coated vanes 401 were arranged, and the base material layer 210 is exposed. Each of the multiple nitrided vanes is height-adjusted to form a vane.

[0055] According to the vane manufacturing method of Example 2, when the nitriding treatment is performed, nitrogen atoms N do not penetrate into the base material layer 210 from the first end face 129d and the second end face 129e, so the region of the base material layer 210 near the first end face 129d and the second end face 129e does not expand. The vane manufacturing method of Example 2 prevents the formation of protrusions on the first end 316 and the second end 317 of the tip surface 129a, similar to the vane manufacturing method of Example 1 described above, because the region of the base material layer 210 near the first end face 129d and the second end face 129e does not expand during the nitriding treatment.

[0056] In a rotary compressor using a vane manufactured by the vane manufacturing method of Example 2 as the upper vane 127T, the absence of protrusions at the first end 316 and the second end 317 prevents the clearance between the upper vane 127T and the upper piston 125T from becoming improper. Therefore, such a rotary compressor, like the rotary compressor 1 of Example 1 described above, can suppress a decrease in sealing performance between the upper vane 127T and the upper piston 125T, thereby suppressing a decrease in compression performance.

[0057] By the way, in the vane manufacturing method of Example 2 described above, the first end face 129d and the second end face 129e are masked by arranging a plurality of post-coated vanes 401 so that nitrogen atoms N do not penetrate into the region near the first end face 129d and the second end face 129e of the base material layer 210. However, masking may be performed by other means. An example of a means for masking the first end face 129d and the second end face 129e is to adhere a nitrogen-impermeable film to the first end face 129d and the second end face 129e. Even when the vane manufacturing method of Example 2 includes such a masking step, it is possible to prevent nitrogen atoms N from penetrating into the region near the first end face 129d and the second end face 129e of the base material layer 210, and to prevent the formation of protrusions on the first end 316 and the second end 317 of the tip surface 129a, similar to the vane manufacturing method of Example 1 described above.

[0058] By the way, although the vane manufacturing method of the embodiment described above includes the height adjustment process in step S7, the height adjustment process in step S7 may be omitted. Even when the height adjustment process is omitted, the vane manufacturing method can suppress the improper clearance between the vane and the piston, suppress the decrease in sealing performance between the vane and the piston, and suppress the decrease in compression performance.

[0059] The rotary compressor 1 in the embodiment described above is a two-cylinder rotary compressor equipped with two cylinders, an upper cylinder 121T and a lower cylinder 121S. However, it may also be a one-cylinder rotary compressor equipped with only one cylinder. Even when the rotary compressor is a one-cylinder rotary compressor, it is possible to suppress the improper clearance between the vane and the piston, suppress the decrease in sealing performance between the vane and the piston, and suppress the decrease in compression performance.

[0060] Although examples have been described above, the examples are not limited to those described above. Furthermore, the components described above include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that fall within the so-called equivalent range. Moreover, the components described above can be combined as appropriate. Furthermore, at least one of various omissions, substitutions, and modifications of the components can be made without departing from the gist of the examples. [Explanation of Symbols]

[0061] 1: Rotary compressor 121S: Lower cylinder 121T: Upper cylinder 125S: Lower piston 125T: Upper piston 127: Bane 127S: Lower vane 127T: Upper vane 128S: Lower vane groove 128T: Upper vane groove 129a: Tip surface 129b: 1st side 129c:Second side 129d: First end surface 129e: 2nd end face 131S: Lower suction chamber 131T: Upper suction chamber 133S: Lower compression chamber 133T: Upper Compression Chamber 140: Intermediate partition plate 160S: Lower end plate 160T: Upper end plate 210: Base material layer 220: High-hardness coating layer on the tip surface 221: First side nitride layer 222: Second side nitride layer 231: First end face high hardness coating layer 232: Second end face high hardness coating layer 302: Vanes after cutting 303: Vane after roughening of the end face 304: Vane after grinding of the tip R surface 305: Vane after precision grinding of the end face 306: Vane after coating 307: Vanes after nitriding treatment

Claims

1. Cylinder and A piston that revolves along the inner circumferential surface of the cylinder, End plates that close both ends of the cylinder, The cylinder chamber, surrounded by the cylinder, the piston, and the end plate, is divided into an intake chamber and a compression chamber by vanes, The aforementioned base is A base material layer consisting of the base material, A high-hardness coating layer covering the tip surface of the base material layer that slides against the outer surface of the piston, The base material layer comprises a nitride layer that covers the side surface of the base material layer that slides against the inner surface of the vane groove of the cylinder, The vane is such that the end face of the base material layer that slides against the end plate is not covered by the nitride layer. Rotary compressor.

2. The vane further comprises another high-hardness coating layer covering the end face. The rotary compressor according to claim 1.

3. A method for manufacturing the vanes used in the rotary compressor according to claim 1, The process of covering the tip surface with the high-hardness coating layer, The process of masking the end face, After the steps of covering the tip surface and masking the end surface are performed, the base material layer is subjected to nitriding treatment so that the side surface is covered by the nitride layer. A method for manufacturing vanes, including

4. In the step of masking the end face, the end face is covered with another high-hardness coating layer formed from the same material as the material forming the high-hardness coating layer. The method for manufacturing a vane according to claim 3.

5. In the step of masking the end face, a plurality of vanes are arranged so that the end face is in contact with other vanes different from the vane. In the process of nitriding the base material layer, the base material layer is subjected to nitriding while the plurality of vanes are arranged in a row. The method for manufacturing a vane according to claim 3.

Images