JP2009174376A - Shaft seal structure for compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft seal structure with few failures by preventing formation of sludge formed by oxidation of high temperature refrigerator oil and inhibiting damage on a slide surface. <P>SOLUTION: In the shaft seal structure 60 provided around a drive shaft 35 of a compressor 1 generating fluid pressure in a housing by rotation of the drive shaft 35, a first seal part 61 preventing leak between the housing and the drive shaft 35 is provided. A second seal part 62 preventing immersion of atmospheric air while allowing leak of refrigerant and refrigerator oil to an outside of the first seal part 61. Heat resistant lubrication medium is filled in a space between the first seal part 61 and the second seal part 62. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a shaft seal structure for a compressor that compresses a fluid to generate a high pressure.

  A compressor used in a vehicle air conditioner has a structure that increases the pressure of a refrigerant in a housing by rotation of a drive shaft. In this case, the rotation input portion of the drive shaft protrudes outward from the housing, and the protruding portion In addition, a configuration in which a pulley is attached is common.

  In such a configuration, a shaft seal structure is attached to the drive shaft for the purpose of preventing outflow of pressure in the housing. As this shaft seal structure, high compression of the refrigerant is progressing. Therefore, various structures have been proposed to deal with it.

For example, in a structure as shown in Patent Document 1 below, a first seal body 32 that separates the outside of the housing between the housing H of the refrigerator compressor and the drive shaft 16 inserted through the inner periphery thereof. And a second seal body 33 that separates the inside of the housing, thereby forming a two-stage seal portion and forming a seal chamber 31 between the first seal body and the second seal body. The sealing chamber 31 is filled with the lubricating oil L that is incompatible with the pressurized fluid, thereby preventing the pressurized fluid (refrigerant gas) from leaking in the machine.
Japanese Patent Laid-Open No. 2004-197683

  However, since this type of shaft seal structure is based on the premise that the sliding contact portion is lubricated by the lubricating oil slightly leaked from the seal portion, the lubricating oil leaked from the second seal body 33 to the seal chamber 31 is assumed. In addition, the pressure in the seal chamber 33 gradually increases due to the refrigerant, and accordingly, the load on the sliding contact portion between the first seal body and the drive shaft 16 increases, and the amount of heat generated at the sliding contact portion also increases. . Since the lubricating oil cannot be completely prevented from leaking from the first seal body 32, the lubricating oil leaked from the first sealing body 31 to the outside of the machine is exposed to oxygen in the atmosphere, Furthermore, oxidation is accelerated by the heat generated at the sliding contact portion. The oxidized lubricating oil becomes a sticky liquid film, and further solidified sludge is formed by mixing carbonized lubricating oil, abrasion powder of the worn sealing body, etc. into the first sealing body 32. The sealing sliding surface will be damaged.

  The damage to the first seal body 32 causes the lubricating oil sealed in the seal chamber 33 to flow out and the atmosphere to enter the seal chamber 33, and the intruded atmosphere causes the second seal body 33 to be outside. In addition, sludge is generated and the sealing sliding surface of the second seal body 33 is damaged, and there is a concern that the refrigerant gas and the refrigerating machine oil in the housing may suddenly leak.

  Therefore, the present invention prevents the lubricating oil leaked from the shaft seal portion from being exposed to oxygen in the atmosphere, and further prevents oxidation from being promoted by the heat generated at the sliding contact portion to generate sludge. The main issue is to provide a high shaft seal structure.

  In order to achieve the above object, a shaft seal structure of a compressor according to the present invention is the shaft seal structure provided around the drive shaft of the compressor that generates fluid pressure in the housing by rotation of the drive shaft. A first seal portion is provided between the housing and the drive shaft to prevent leakage of refrigerant and refrigeration oil flowing in the machine, while permitting leakage of the refrigerant and refrigeration oil outside the first seal portion. The second seal portion is provided to prevent air from entering (Claim 1).

  Thereby, in the 1st seal part, it is possible to prevent leakage of the refrigerant and refrigeration oil in the machine, and even when the refrigerant and refrigeration oil leak from the first seal part, Since the leakage of the leaked refrigerant and the refrigerating machine oil is allowed to flow out of the apparatus, the leaked refrigerant and the refrigerating machine oil do not increase the pressure in the space between the first seal part and the second seal part. The load of the sliding contact portion of the seal portion 2 can be kept low, and heat generation at the sliding contact portion can be minimized. As a result, even if the refrigerating machine oil leaked from the second seal part to the atmosphere side is exposed to oxygen, oxidation is not promoted, the generation of sludge in the second seal part is prevented, and the sliding contact part is damaged by the sludge. Can be prevented.

  Moreover, even if the refrigerating machine oil leaked from the first seal portion is placed under a high temperature due to heat generated by the sliding contact portion of the first seal portion, the second seal prevents the air from entering. Leaked refrigeration oil will not oxidize. Accordingly, it is possible to prevent the generation of sludge at the first seal portion and to prevent the sliding contact portion from being damaged by the sludge.

  In the structure described above, a heat-resistant lubricating medium may be enclosed in a space between the first seal portion and the second seal portion (claim 2). By sealing the lubricating medium, the air remaining in the space between the first seal part and the second seal part is eliminated, and the refrigeration oil leaked from the first seal part is exposed to the residual oxygen and oxidized. It is possible to prevent the generation of sludge caused by.

  Here, since the heat-resistant lubricating medium sealed in the space between the first seal portion and the second seal portion only has to exhaust the air remaining in the space, not only refrigeration oil but also fluorine System-based or silicon-based grease may be used (claims 3 and 4).

    Such sealing of the lubricating medium in the space between the first seal portion and the second seal portion is performed by previously attaching the lubricating medium to the drive shaft without using a special device. (Claim 5).

  Further, the sealing of the lubricating medium into the space between the first seal portion and the second seal portion is performed after the lubricating medium is injected through the injection hole formed in the drive shaft and then attached to the drive shaft. The injection hole is sealed by a fixing member (for example, a mounting bolt for attaching a pulley to the driving shaft) for fixing the member to the driving shaft (Claim 6), and is formed in the housing. After injecting the lubricating medium through the injection hole, the injection hole may be sealed by a member (for example, a pulley bearing) mounted on the housing (claim 7).

    In such a configuration, the lubricating medium is injected before the assembly of the member to be mounted on the drive shaft or the housing, and the injection hole is sealed by assembling the member to the drive shaft or the housing after the injection. Therefore, the sealing of the lubricating medium is completed in the course of a series of assembly work. Moreover, since the injection hole can be sealed with existing components, a special member for sealing the injection hole is not required.

  Furthermore, if the second seal part is integrated with the first seal part (Claim 8), both the seal parts can be assembled at the same time, and the number of assembling steps can be reduced. Further, if the lubricating medium outflow suppression means is provided in the space between the first seal portion and the second seal portion (claims 9 and 10), the first seal portion and the second seal portion Accordingly, it is possible to suppress the outflow of the lubricating medium sealed in the space between them, and to keep the lubricating medium in the space.

    Further, a capture member that captures the refrigeration oil leaked from the second seal and the heat-resistant lubricating medium enclosed in the space between the first seal portion and the second seal portion outside the second seal. (Claim 11). Thereby, since the leaked refrigeration oil and the heat-resistant lubricating medium are prevented from scattering outside the compressor, the generation of a strange odor and the slippage of the drive belt can be prevented.

  As described above, according to the present invention, the first seal portion functions to prevent leakage of refrigerant and refrigeration oil flowing in the machine, and even when refrigerant and refrigeration oil leak from the first seal portion. In the second seal portion, the refrigerant and the refrigerating machine oil are allowed to flow out of the apparatus. Therefore, the leaked refrigerant and the refrigerating machine oil cause a gap between the first seal portion and the second seal portion. The pressure in the space does not increase, the load on the sliding contact portion of the second seal portion is kept low, and heat generation at the sliding contact portion can be minimized. As a result, even if the refrigerating machine oil leaked from the second seal part to the atmosphere side is exposed to oxygen, oxidation is not promoted, the generation of sludge in the second seal part is prevented, and the sliding contact part is damaged by the sludge. Can be prevented. Furthermore, since the second seal part prevents air from entering, the refrigeration oil leaked from the first seal part is prevented from being exposed to oxygen and oxidized to prevent the generation of sludge. It becomes possible to prevent.

  Further, by adopting a configuration in which a heat-resistant lubricating medium is sealed in the space between the first seal portion and the second seal portion, it becomes possible to exclude air remaining in the space, and in the space It is possible to more reliably prevent leakage of refrigerating machine oil from sludge and damage to the seal portion, thereby extending the service life of the shaft seal structure.

  The lubricating medium is enclosed in the space between the first seal portion and the second seal portion by attaching the lubricant medium to the drive shaft in advance and then assembling the first and second seal portions. However, with such a configuration, it is possible to easily enclose the lubricating medium without drilling the compressor.

Further, the enclosure of the lubricating medium into the space between the first seal portion and the second seal portion is as follows:
The lubricating medium is injected through an injection hole formed in the drive shaft, and then the injection hole is sealed with a fixing member for fixing the member attached to the drive shaft to the drive shaft. The lubricating medium may be injected through the injection hole formed in the housing, and then the injection hole may be sealed with a member attached to the housing. Thus, the injection hole can be sealed, so that the structure of the compressor is not complicated and the number of parts is not increased.

  Further, if the second seal portion is integrated with the first seal portion, both the seal portions can be assembled at the same time, and the number of assembling steps can be reduced. In addition, if a configuration in which a lubricating medium outflow suppression means such as a labyrinth seal is provided in the space between the first seal portion and the second seal portion, the lubrication enclosed in the space between the first and second seal portions is provided. The medium can remain in the space.

  Further, the refrigerating machine oil leaked from the second seal and the heat-resistant lubricating medium enclosed in the space between the first seal portion and the second seal portion are captured outside the second seal. If the members are provided, it is possible to prevent the leaked refrigeration oil and the heat-resistant lubricating medium from being scattered outside the compressor, thereby preventing the generation of a strange odor and slipping of the drive belt.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best embodiment of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a piston reciprocating variable displacement swash plate compressor used in a refrigeration cycle using CO2 as a refrigerant. First, the compressor 1 will be described. The cylinder block 2, the rear head 4 assembled to the rear side (right side in the figure) of the cylinder block 2 via the valve plate 3, and the front side ( And a front head 6 which is assembled so as to close the left side in the figure and defines a crank chamber 5. These front head 6, cylinder block 2, valve plate 3, and rear head 4 is fastened in the axial direction by fastening bolts 7 and constitutes a housing of the whole compressor.

  The cylinder block 2 has a large-diameter portion 2a substantially equal to the diameter of the front head 6, and a small-diameter portion 2b having a small diameter on the left side in the drawing. The small-diameter portion 2b is located in the front head 6. It is inserted and fixed. The small-diameter portion 2b of the cylinder block 2 is formed with a recess 9 at the center thereof, and a plurality of cylinder bores 10 are formed in the circumferential direction around the recess 9, and each of the cylinder bores 10 has a single head. The piston 11 is inserted so as to freely reciprocate.

  The valve plate 3 is interposed between the cylinder block 2 and the rear head 4 to form a suction hole 15 that communicates the cylinder bore 10 and a suction chamber 18 described below, and discharges the cylinder bore 10 and the discharge described below. A discharge hole 16 communicating with the chamber 19 is formed. The suction hole 15 is opened and closed by a suction valve (not shown), and the discharge hole 16 is opened and closed by a discharge valve (not shown) according to the pressure difference between the front and rear of the valve body.

  The rear head 4 has a lubricating oil (refrigerating machine oil) recovery chamber 17 formed at the center of the interior thereof, a suction chamber 18 formed at the outer periphery thereof, and a discharge chamber 19 formed at the outer periphery thereof. The suction chamber 18 is connected to a suction port 21 via a suction passage 20 and sucks refrigerant from an external refrigeration circuit. A foreign matter separator 22 is installed at the suction port 21 to separate foreign matter flowing in from the external refrigeration circuit and prevent foreign matter from entering the suction chamber.

  The discharge chamber 19 is connected to a lubricating oil separator 23. The lubricating oil separation device 23 is configured to include a separation chamber 24 in a cylindrical space and a lead-out pipe 25 arranged concentrically therein, and the refrigerant gas flowing out from the discharge chamber 19 is placed in the separation chamber 24. The lubricating oil is separated while being swirled, and the separated lubricating oil is dropped downward and guided to the lubricating oil recovery chamber 17 through a passage 26 connected to the lower portion of the separation chamber 24. The refrigerant from which the lubricating oil has been separated flows out through the outlet pipe 25 and out of the discharge port 28 to the external refrigeration circuit through the check valve 27.

  A pressure control valve 30 is provided in the rear head 4. The pressure control valve 30 controls the pressure in the crank chamber 5 by adjusting the flow rate of the refrigerant flowing from the discharge chamber 19 into the crank chamber 5. ing. Although this method is an inlet control method, even if an outlet control method that controls the pressure in the crank chamber 5 by adjusting the flow rate of the refrigerant flowing out from the crank chamber 5 to the suction chamber 18 is used, An inlet / outlet control method for controlling the pressure in the crank chamber 5 by adjusting the refrigerant flow rate flowing into the crank chamber 5 and the refrigerant flow rate flowing out from the crank chamber 5 into the suction chamber 18 may be adopted. An adapter 32 has a function of extending the lubricant recovery chamber 17 to the cylinder block 2 and fixing the rear head 4 to the cylinder block 2.

  The front head 6 forms a crank chamber 5 with the cylinder block 2, and the front end portion (left end portion in FIG. 1) of the front head 6 is closed by an end wall 6a. The crank chamber 5 accommodates a drive shaft 35 having one end protruding from the front head 6.

  The right side of the drive shaft 35 is supported by a radial bearing 36 disposed in a recess 9 formed in the cylinder block 2 and a thrust bearing 37 urged by a spring load in the axial direction. . Further, the middle of the drive shaft 35 has a plain bearing 40 provided inside a thrust flange 39 fixed to the end wall 6 a of the front head 6, and a step formed on the thrust flange 39 and the drive shaft 35. 38 is supported by a thrust bearing 41 interposed therebetween.

  The swash plate 42 is formed in a disc shape having a predetermined thickness, and can tilt around a support shaft 44 that penetrates a long hole 43 formed in the drive shaft 35 in the axial direction of the drive shaft 35. Further, a pin 46 protrudingly fixed to the drive shaft 35 is engaged with a longitudinal groove 47 of the swash plate 42 so as to rotate integrally with the rotation of the drive shaft 35. . At the peripheral portion of the swash plate 42, a tail portion 11 a of the piston 11 protruding into the crank chamber 5 via a pair of shoes 48 is moored.

  Therefore, when the drive shaft 35 rotates, the swash plate 42 rotates integrally with the rotation of the drive shaft 35, and this rotational motion is converted into the reciprocating linear motion of the piston 11 via the shoe 48. 10, the volume of the compression chamber 50 formed between the piston 11 and the valve plate 3 is changed. A support shaft 44 that supports the swash plate 42 is externally inserted into the guide tube 52 and is urged toward the cylinder block 2 by a spring 51. The guide tube 52 communicates with the lubricating oil recovery chamber 17 and supplies lubricating oil through a supply hole 53 to a shaft seal structure 60 described below on the front side.

  One end of the drive shaft passes through the cylindrical portion 6b to attach a pulley and protrudes to the outside. A pulley 56 is attached to the protruding tip by a bolt 55 screwed in the axial direction. The pulley 56 is rotatably supported by the bearing 57 on the outer peripheral wall of the cylindrical portion 6b.

  As shown in an enlarged view in FIG. 2, the shaft seal structure 60 according to the first embodiment of the present invention includes a first seal portion 61 and a second seal portion 62, and the first seal portion. Reference numeral 61 denotes a fixed ring 65 which is provided on the mounting portion 63 formed on the cylindrical portion 6b of the front head 6 via an O-ring 64 and fixed with a predetermined clearance with respect to the drive shaft, and the fixed ring A rotating ring 67 that is disposed on the crank chamber side from 65 and is movably mounted in the axial direction via an O-ring 66 provided on the outer periphery of the driving shaft 35, and is driven on the back side of the rotating ring 67 An annular metal case 69 locked to a step portion 68 formed on the outer peripheral surface of the shaft 35, and a leaf spring 70 elastically mounted between the metal case 69 and the rotating ring 67. Yes.

  A plurality of engagement claws 73 extending in the distal direction of the drive shaft 35 are formed at the distal end portion of the metal case 69, and the engagement claws 73 are axially formed on the outer peripheral surface of the rotating ring 67. Thus, the rotary ring 67 is rotated together with the drive shaft 35 and receives a biasing force of the leaf spring 70 and is brought into contact with the fixed ring 65. A sealing sliding surface 76 is formed by a contact portion between the rotating ring 67 and the fixed ring 65.

  The first seal portion 61 prevents the refrigerating machine oil supplied from the supply hole 53 and the refrigerant guided through the clearance between the thrust flange 39 and the drive shaft 35 from flowing out of the housing. As the pressure inside the housing increases, the surface pressure of the sealing sliding surface 76 increases.

  The second seal portion 62 is on the outer side (atmosphere side) than the stationary ring 65, and is configured by attaching a lip 79 to a mounting portion 78 formed on the cylindrical portion 6 b of the front head 6. The lip 79 is made of rubber or resin, has a U-shaped cross section, and its opening side is directed outward (atmosphere side), and the contact surface with respect to the drive shaft 35 is away from the fixed ring 65 (anti-fixed ring). It is extended to the side). The second seal 62 is fixed away from the first seal 61 (fixed ring 65) and is in close contact with the drive shaft 35. Since the closed space 81 is formed and the opening side is directed to the outside, leakage of fluid (refrigerant and refrigeration oil) from the inside to the outside is allowed, but the fluid (air) from the outside to the inside is permitted. The structure prevents entry.

    In the above configuration, the first seal portion 61 prevents leakage of refrigerant and refrigeration oil. However, since the leakage cannot be completely eliminated, the refrigerant and refrigeration that have flowed out through the first seal portion 61 are prevented. The machine oil is stored in the space 81, and when the space 81 rises above a predetermined pressure, the second seal portion 62 is expanded and discharged to the outside. As a result, the pressure in the space 81 is kept below a predetermined pressure, and the load on the sliding contact portion of the second seal portion is kept below the initial tightening allowance. Therefore, sliding heat generation of the second seal portion is minimized, and a high temperature state that contributes to sludge generation is prevented.

  Furthermore, since the lip 79 is in close contact with the drive shaft 35 and the opening side is directed to the outside (atmosphere side), entry of air from the outside is prevented. For this reason, since intrusion of oxygen in the air is prevented, generation of sludge caused by oxidation of the refrigerating machine oil leaked into the space 81 through the first seal portion 61 is prevented, and the first and first It becomes possible to prevent damage to the two seal portions.

  In the configuration described above, the space 81 between the first seal portion 61 and the second seal portion 62 is filled with a lubricating medium such as fluorine-based or silicon-based grease or refrigeration oil. This lubricating medium is heat-resistant and reduces deterioration due to heat generated at the sliding contact portion of the seal portion. In order to enclose the lubricating medium in the space 81, the lubricating medium is attached in advance to the sliding portion of the drive shaft 35 before the drive shaft 35 is assembled, and then the first seal portion 61 and the second seal portion are connected. This is done by attaching the seal portion 62.

  As described above, when the lubricating medium is sealed in the space 81, the air remaining in the space 81 can be eliminated, so that the lubricating medium is not oxidized by the remaining air (oxygen), and the service life of the shaft seal structure is eliminated. Can be extended.

The sealing of the lubricating medium in the space 81 is not limited to the above-described sealing at the time of assembling the compressor main body, and may be configured to be sealed after the compressor main body is assembled.
As an example of such a configuration, as shown by a two-dot chain line in FIGS. 1 and 2, an injection hole 83 for injecting a lubricating medium is provided with a longitudinal hole formed in the axial direction from the tip of the drive shaft 35 and A horizontal hole is formed so as to face the space 81 in the radial direction, and the tip of the vertical hole is communicated with a female screw portion 86 into which the bolt 55 is screwed.

  In order to enclose the lubricating medium using the injection hole 83, first, an injection device (not shown) is connected to the injection hole 83, and pressure is applied to inject the lubricating medium into the space 81. When the enclosure in the space 81 is completed, the injection hole 82 is sealed by screwing the bolt 55 for attaching the pulley 56 to the female screw portion 86.

  As another configuration example, similarly, as shown by a two-dot chain line in FIGS. 1 and 2, an injection hole 84 for injecting a lubricating medium is formed in the radial direction of the cylindrical portion 6 b of the front head 6, and one end thereof is a space 81. The other end is opened to the outer peripheral surface of the cylindrical portion 6b to which the bearing 57 of the pulley 56 is mounted.

  The injection of the lubricating medium using the injection hole 84 is performed by connecting an injection device (not shown) to the injection hole 84 and applying pressure to inject the lubricating medium into the space 81 before the pulley 56 is assembled. . Then, when the sealing in the space 81 is completed, the injection hole 84 is sealed by the bearing 57 by assembling the pulley 56 via the bearing 57.

  According to the configuration using these injection holes, it is possible to complete the sealing of the lubricating medium in the process of assembling the pulley 56. In addition, since the injection hole can be sealed with existing parts, a special member for sealing the injection hole is not required, the complexity of the compressor structure can be avoided, and the number of parts does not increase. It becomes possible.

      FIG. 3 shows a shaft seal structure 60 according to the second embodiment of the present invention. In this example, a lip seal 90 constituting a first seal part made of rubber or resin is attached to the inside of the machine via a retainer 92, and the tip end side of the lip seal 90 is connected to the crank chamber 5 side. It is bent and brought into contact with the outer peripheral surface of the drive shaft 35 so as to be able to slide. Further, on the outside (atmosphere side) of the lip seal 90, a lip 95 constituting a second seal portion made of rubber or resin is attached to the metal case 91 via an interposed member 94 having a hole 93. The tip end side of 95 is bent to the opposite side to the crank chamber and is brought into contact with the outer peripheral surface of the drive shaft 35 so as to be slidable. Reference numeral 96 denotes a retaining ring for fixing the shaft seal structure 60.

    Therefore, the lip seal 90 has a configuration in which refrigerant and refrigeration oil are difficult to leak from the inside of the machine, and the lip 95 is not exposed to the outside of the machine even when the refrigerant and refrigeration oil in the machine leaks through the lip seal 90. It is configured to prevent intrusion of air from outside the machine while allowing discharge.

An injection hole 84 formed in the cylindrical portion 6b of the front head 6 communicates with a space 81 formed between the lip seal 90 and the lip 95, and a heat-resistant lubricating medium is passed through the injection hole 84. Is to be enclosed.
Since other configurations are the same as those in the above-described embodiment, the same numbers are assigned to the same portions, and descriptions thereof are omitted.

  Even in such a configuration, the same operational effects as the above configuration example can be obtained, and the infiltration of air from the outside is prevented by the lubricating medium sealed in the space 81 and the lip seal 90 and lip 95, and the sludge is prevented. Occurrence and damage to the seal are prevented.

FIG. 4 shows a shaft seal structure 60 according to a third embodiment of the present invention. In this example, the second seal portion 62 is integrated with the first seal portion 61, and the second seal portion 62 is formed on the mounting portion 63 formed on the cylindrical portion 6 b of the front head 6. The lip 98 is fixed together with the fixed ring 65 of the first seal portion 61. The lip 98 has an L shape as a whole, and the tip end side is bent to the opposite side of the crank chamber and is in slidable contact with the outer peripheral surface of the drive shaft 35.
Also in this configuration, a heat-resistant lubricating medium is enclosed in a space 81 surrounded by the lip 98 and the fixed ring 65 and the rotating ring 67 of the first seal portion 61.

  In this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. In this embodiment, instead of the leaf spring 70 of the first embodiment, a coil spring 70a is used. And a retainer 97 for receiving the coil spring 70a.

    Therefore, also in the third embodiment, air intrusion from the outside is prevented by the lip 98 and air in the space 81 is excluded by the lubricating medium sealed in the space 81. Therefore, sludge accompanying oxygen intrusion. It is possible to prevent damage to the seal portion due to the occurrence of. As described above, the lubricating medium is sealed in the space 81 by adhering to the drive shaft 35 or by injecting the lubricating medium through the injection hole formed in the drive shaft 35. Done in Further, in this configuration, since the lip 98 constituting the second seal portion 62 is integrated with the first seal portion 61, the first seal portion 61 and the second seal portion 62 are attached at the same time. This makes it possible to easily attach these seal portions.

  FIG. 5 shows a shaft seal structure 60 according to a fourth embodiment of the present invention. In this example, a first seal portion 61 and a second seal portion 62 are provided. The first seal portion 61 includes a rotating ring 67 held by a metal case 69 and a coil spring 70a that presses the rotary ring 67. And a stationary ring 65 attached to an attachment portion 72 formed on the cylindrical portion 6b of the front head 6 via an O-ring 64. A space 81 between the first seal portion 61 and the second seal portion 62 (in this example, inside the fixed ring 65) is integrated with the first seal portion 61 (integrated with the fixed ring 65). A labyrinth seal 99 is provided.

  The second seal portion 62 is provided outside the fixed ring 65 and is mounted on a mounting portion 78 formed on the cylindrical portion 6b of the front head 6, and the tip side is opposite to the crank chamber (fixed ring). And a lip 100 made of rubber or resin that is slidably contacted with the outer peripheral surface of the drive shaft 35. Further, in this configuration, a labyrinth seal 99 is disposed in a space 81 between the first seal portion 61 and the second seal portion 62 and a heat-resistant lubricating medium is enclosed. In other configurations, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

    Therefore, even in such a configuration, the same effect as the above-described configuration example can be obtained, the intrusion of air from the outside is prevented by the lip 100, and the air in the space is sealed by the lubricating medium sealed in the space 81. Therefore, it is possible to prevent the seal portion from being damaged due to the generation of sludge due to the entry of oxygen. Further, since the labyrinth seal 99 is provided in the space 81, the lubricating medium enclosed in the space 81 can be easily held, and the effect of preventing the generation of sludge and the breakage of the seal portion can be maintained. As described above, the lubricating medium is sealed in the space 81 by adhering to the drive shaft 35 in advance, or through an injection hole formed in the drive shaft 35 or the cylindrical portion 6b of the front head 6 via this injection hole. This is done by injecting a lubricating medium.

  6 shows a shaft seal structure 60 according to a fifth embodiment of the present invention. In this example, the second seal portion 62 of the third embodiment described in detail above is integrated with the first seal portion 61, and further outside the second seal 62 (atmosphere side). Is provided with a capture member 102 that captures felt or nonwoven refrigerator oil and / or the lubricating medium. Specifically, the capture member 102 is attached to a mounting portion 103 formed on the cylindrical portion 6 b of the front head 6 by a retaining ring 104, and a tip thereof is in slidable contact with the outer peripheral surface of the drive shaft 35.

  Also in this configuration, a heat-resistant lubricating medium is sealed in a space surrounded by the lip 98 and the fixed ring 65 and the rotary ring 67 of the first seal portion 61. Also in the fifth embodiment, the same parts as those in the third embodiment are denoted by the same reference numerals and description thereof is omitted.

  Therefore, in the fifth embodiment, the first seal portion 61 prevents leakage of the refrigerant and the refrigerating machine oil. However, since the leak cannot be completely eliminated, the first seal portion 61 is interposed. The refrigerant and the refrigerating machine oil that have flowed out in this manner are stored in the space 81. When the space 81 rises above a predetermined pressure, the second seal portion 62 is expanded and discharged to the outside.

  As a result, the pressure in the space 81 is kept below a predetermined pressure, the load on the sliding portion of the second seal portion is kept below the initial tightening allowance, and the same effect as the third embodiment is achieved. However, the refrigerating machine oil and the heat-resistant lubricating medium that are discharged to the outside by expanding the second seal portion 62 are captured by the capturing member 102. This prevents the leaked refrigeration oil and the heat-resistant lubricating medium from scattering outside the compressor, prevents the generation of a strange odor, and also has a pulley 56 adjacent thereto and a driving belt for the bodywork (not shown). It can be prevented from slipping. Of course, the capture member 102 according to the fifth embodiment can be applied not only to the third embodiment but also to the first, second, and fourth embodiments.

  In the above-described shaft sealing structure 60, five types of embodiments are shown as the configuration of the first seal portion 61, but the configuration is not limited to these configurations. In the above-described configuration, the lip 79, 95, 98, 100 of the second seal portion 62 is shown as a lip seal type. However, the configuration may be changed to an O-ring or a mechanical seal having the same function. .

It is sectional drawing of the compressor with which the shaft seal structure of this invention is implemented. It is an expanded sectional view of the 1st example of the shaft seal structure of this invention. It is sectional drawing of the 2nd Example of the shaft seal structure of this invention. It is sectional drawing of the 3rd Example of the shaft seal structure of this invention. It is sectional drawing of the 4th Example of the shaft seal structure of this invention. It is sectional drawing of the 5th Example of the shaft seal structure of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Cylinder block 3 Valve plate 4 Rear head 5 Crank chamber 6 Front head 6b Cylindrical part 10 Cylinder bore 11 Piston 15 Suction hole 16 Discharge hole 17 Lubricant oil recovery chamber 22 Foreign material separator 23 Lubricant oil separator 30 Pressure control valve 35 Drive Shaft 39 Thrust flange 42 Swash plate 44 Support shaft 50 Compression chamber 55 Bolt 56 Pulley 57 Bearing 60 Shaft seal structure 61 First seal portion 62 Second seal portion 65 Fixed ring 67 Rotating ring 76 Closely sliding surface 79 Lip 81 Space 83 Injection hole 84 Injection hole 86 Bolt screw female thread part 90 Lip seal 95 Lip 99 Labyrinth seal 100 Lip 102 Capture member

Claims (11)

In the shaft seal structure provided around the drive shaft of the compressor that generates fluid pressure in the housing by rotation of the drive shaft,
A first seal portion is provided between the housing and the drive shaft to prevent leakage of refrigerant and refrigeration oil flowing in the machine, and leakage of the refrigerant and refrigeration oil is allowed outside the first seal portion. A shaft seal structure for a compressor, characterized in that a second seal portion for preventing air from entering is provided.   2. The shaft seal structure for a compressor according to claim 1, wherein a heat-resistant lubricating medium is enclosed in a space between the first seal portion and the second seal portion.   The shaft sealing structure for a compressor according to claim 2, wherein the lubricating medium is refrigeration oil.   The shaft sealing structure for a compressor according to claim 2, wherein the lubricating medium is fluorine-based or silicon-based grease.   3. The enclosure of the lubricating medium in the space between the first seal portion and the second seal portion is performed by previously attaching the lubricating medium to the drive shaft. Compressor shaft seal structure.   The lubricant is sealed in the space between the first seal portion and the second seal portion after being injected through an injection hole formed in the drive shaft and then mounted on the drive shaft. 3. The shaft seal structure for a compressor according to claim 2, wherein the injection hole is sealed by a fixing member for fixing the member to the drive shaft.   The lubricating medium is sealed between the first seal portion and the second seal portion after being injected through an injection hole formed in the housing, and then injected by a member attached to the housing. The shaft sealing structure for a compressor according to claim 2, wherein the shaft sealing structure is performed by sealing the hole.   The shaft seal structure for a compressor according to claim 1, wherein the second seal portion is integrated with the first seal portion.   2. The shaft seal structure for a compressor according to claim 1, wherein a lubricating medium outflow suppression means is provided in a space between the first seal portion and the second seal portion.   The shaft seal structure for a compressor according to claim 9, wherein the lubricating medium outflow suppression means is a labyrinth seal.   The compressor shaft seal according to claim 1, wherein a capture member that captures the refrigerating machine oil and / or the lubricating medium leaked from the second seal portion is provided outside the second seal portion. Construction.