JP2006242061A - Mechanical seal structure for compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simultaneously prevent shortage of oil on a sliding surface at a time of operation stop of a compressor, creation of sludge due to retention of oil leaking to an inner side part of the sliding surface at a time of compressor operation, and trouble of not supplying sufficient oil to the sliding surface. <P>SOLUTION: A rotary ring 40 and a fixed ring 41 retained by a housing of a compressor on an opposite side of an open air side in relation to the rotary ring are included. A sliding projection part 44 is provided on one of the rotary ring 40 and the fixed ring 41. An oil storage space 45 is defined by the rotary ring 40, fixed ring 41, the sliding projection part 44 and a side surface of a drive shaft 7 inside of the sliding surface S. A first oil supply passage 46 is provided on the drive shaft 7. One end of the oil supply passage 46 is opened to the oil storage space 45. A second oil supply passage 47 is formed between the fixed ring 41 and the drive shaft 7. Consequently, the oil storage space 45 forms a part of an oil circulation passage communicating to a crank chamber 9 defined in a housing 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement in a structure in which a peripheral surface of a drive shaft of a compressor and an inner surface of a cover member facing the peripheral surface of the drive shaft are sealed with a mechanical seal.

In recent years, as the use of high-pressure CO ₂ refrigerant as a refrigerant is becoming more common, the peripheral surface of the drive shaft of the compressor and the inner surface of the cover member facing the peripheral surface of the drive shaft are shaft sealed. In doing so, mechanical seals such as those shown in Patent Documents 1 to 3 are often used instead of oil seals using lips.

  Among these, the structure of the mechanical seal described in Patent Document 1 will be described. The rotating ring that rotates integrally with the drive shaft is disposed closer to the crank chamber than the fixed ring that is fixed to the inner peripheral surface of the housing of the compressor. Thus, since no gap is formed between the rotating ring and the drive shaft, etc., the sealing fluid is a sliding surface formed by closely contacting the opposing side surfaces of the rotating ring and the fixed ring. It will be enclosed by the outer peripheral side.

  However, the structure of the mechanical seal requires that an appropriate amount of oil is always supplied onto the sliding surface. In the structure of the mechanical seal shown in Patent Document 1, the vicinity of the sliding surface when the compressor stops rotating. The oil supplied to the oil is separated from the sliding surface due to the action of gravity, and it is difficult to always hold the oil in an appropriate amount on the sliding surface.

  For such a problem of running out of oil in Patent Document 1, as shown in Patent Document 2, a seal space is defined using a second seal member different from the mechanical seal, By holding the oil supplied from the supply path in this seal space, an appropriate amount of oil is always supplied on the sliding surface formed by closely contacting the opposing side surfaces of the rotating ring and the fixed ring. This is already known.

  On the other hand, in the structure of the mechanical seal in which the opposing side surfaces of the rotating ring and the stationary ring are in close contact with each other to form a sliding surface, it is difficult to completely prevent a small amount of oil from leaking from the clearance between the sliding surfaces. However, in the structure in which the sealing fluid is sealed on the outer diameter side of the sliding surface as in Patent Document 1, the leaked oil stays on the inner edge side of the sliding projection due to the centrifugal force when the drive shaft rotates. There was a problem that this accumulated oil became sludge.

Furthermore, in Patent Document 2, the lubricating oil is supplied from the outside. However, in a compressor mounted as a refrigeration cycle for an automotive air conditioner, it is not feasible, and the oil circulation path is compressed. It is necessary to prepare inside the aircraft. With respect to this point, as shown in Patent Document 3, a passage is provided in the drive shaft, and the low pressure chamber or the high pressure chamber is communicated with the crank chamber via this passage. A configuration in which refrigerant and oil are circulated using differential pressure is already known.
JP 2001-4034 A UK Patent Application GB 2313416 A Japanese Utility Model Publication No. 52-21209

  However, as shown in Patent Document 2, in the configuration in which the seal space is isolated using the second seal member, the oil is retained in a large amount in the region where the oil can be supplied to the sliding surface, but this is retained. Since it is difficult to circulate the oil, the oil becomes relatively hot at the time of high speed rotation of the compressor, and oil sludge is generated near the sliding surface, which causes a problem that the sliding surface is damaged. In addition, since there is always a large amount of oil around the sliding surface, blistering is likely to occur on the sliding surface, and there is also a problem that the sliding surface is damaged by the occurrence of this blister. In connection with this, in patent document 2, the inconvenience that it is difficult to maintain airtightness by a mechanical seal for a long period of time occurs.

  Further, in the configuration shown in Patent Document 3, the oil circulation path for supplying oil to the sliding surface is located at a position relatively away from the sliding surface. Insufficient supply of oil to the surface causes problems such as generation of oil sludge due to heat generation and wear of the sliding surface.

  Therefore, the present invention prevents oil from running out on the sliding surface when the compressor is stopped, prevents sludge from staying inside the sliding surface of the leaked oil during rotation of the compressor, and It is an object of the present invention to provide a compressor mechanical seal structure that simultaneously prevents the problem that oil is not sufficiently supplied to a sliding surface.

  The mechanical seal structure of the compressor according to claim 1 includes a rotary ring that is rotated integrally with a drive shaft of the compressor, and compresses the rotary ring on the side opposite to the outside air side in the axial direction of the drive shaft. A non-rotating stationary ring that is held by the housing of the machine, and the rotating ring and the stationary ring are sliding protrusions protruding from at least one of the rotating ring and the stationary ring. It is in close contact with the sliding surface formed by the opposing side surface and the opposing side surface not having this sliding protrusion, and at the side surface of the rotating ring, the fixed ring, the sliding protrusion, and the drive shaft. An oil storage space is defined on the inner side of the sliding surface, a first oil supply passage is provided on the drive shaft, at least one end of the oil supply passage is opened to the oil storage space, and the fixing is performed A second oil supply passage is formed between the ring and the drive shaft In Rukoto, the oil receiving space is communicated with a crank chamber defined in the housing, it is characterized in that the form part of the oil circulation path. The sliding protrusion is made of a self-lubricating sliding material, and at least the sliding contact portion with the sliding protrusion on the opposite side is relatively hard.

  In the mechanical seal structure of the compressor according to claim 2, a first seal member is interposed between the rotary ring and the drive shaft, and the outside air in the axial direction of the drive shaft with respect to the rotary ring. On the side, the rotating ring removal preventing means is fitted to the drive shaft. The disconnection preventing means is a snap ring. The drop prevention means is a metal ring press-fitted and fixed to the drive shaft. Furthermore, the removal preventing means is a lock nut fastened to the drive shaft.

  The fixed ring according to claim 3 is held by an annular step provided in the housing via a second seal member, and is urged toward the rotating ring by an urging force of an elastic mechanism. It is a feature. The elastic mechanism defines a space by the retainer and the stationary ring that are formed of a portion in contact with the annular step portion and a portion extending in the axial direction of the drive shaft, and an elastic member is interposed in the space. (Claim 4). Examples of the elastic member include a spring and an O-ring.

  The mechanical seal structure of the compressor according to claim 8 is characterized in that a support member is attached to the drive shaft outside the rotating ring in the axial direction. The support member is a reinforcing member for preventing the pushing force of the rotating ring due to the internal pressure of the compressor from being transmitted to the drop prevention means via the rotating side seal member, and the sliding member generated in the rotating ring. A heat radiating member for dissipating dynamic heat to the power transmission mechanism of the compressor via outside air or a drive shaft.

  The annular stepped portion according to claim 10 is configured such that the position on the radial side of the inner peripheral surface with which the second seal member abuts in an airtight manner is closer to the compressor than the outer peripheral side edge of the sliding surface. The position is located on the center side and on the outer side of the compressor with respect to the inner peripheral side edge of the sliding surface.

  Therefore, according to these inventions, the oil storage space is defined by the inside of the sliding surface surrounded by the fixed ring, the protrusion, and the drive shaft, and this oil storage space serves as a trap. Even when the machine stops rotating, the oil that has been supplied near the sliding surface does not leave the sliding surface due to the action of gravity, and the oil is always held in the oil storage space. It is possible to prevent oil from running out on the surface.

  Further, according to these inventions, the drive shaft is provided with the first oil supply passage extending along the axial direction, and at least one of the first oil supply passages is opened in the oil containing space and communicated directly. And providing a second oil supply passage between the inner peripheral surface of the stationary ring and the side surface of the drive shaft so as to communicate with the oil storage space and the crank chamber defined in the housing. Constitutes a part of the oil circulation path, so that it is possible to prevent the amount of oil remaining in the oil accommodating space from being excessive or conversely insufficient. Thereby, generation | occurrence | production of the blister on a sliding surface and generation | occurrence | production of the oil sludge near sliding surface can be prevented simultaneously.

  According to these inventions, oil leaking from the oil storage space through the clearance of the sliding surface is excluded in the direction away from the sliding surface by centrifugal force during operation of the compressor. Oil sludge can be prevented from being generated in the vicinity of the sliding surface.

  In particular, according to the second aspect of the present invention, since the rotary ring is attached to the drive shaft via the first seal member, it is not completely connected to the drive shaft, and the oil storage space While the airtightness of the drive shaft can be kept to some extent along the axial direction of the drive shaft, the rotating ring is urged by the prevention means to come off due to the difference in pressure between the inside and outside pressure of the compressor. Even with such a structure, the rotary ring can rotate in a pair in synchronization with the drive shaft.

  In particular, according to the invention described in claim 3, since the stationary ring is also attached to the annular step portion of the housing via the second seal member, it is not completely fixed to the annular step portion, Even if the rotating ring is urged and moved to the removal preventing means side as described above, the stationary ring is also urged by the elastic mechanism to the rotating ring side. Since it moves in the axial direction, the sliding surface is always kept in close contact with no gap. For this reason, it can suppress effectively that oil leaks from the clearance gap between sliding surfaces. As described above, since the rotary ring can move in the axial direction, a good adhesion state is maintained even when the pressure in the compressor becomes lower than the external atmospheric pressure (evacuation before charging the refrigerant).

  In particular, according to the eighth aspect of the invention, the supporting member can prevent the pushing force of the rotating ring caused by the internal pressure from being transmitted to the removal preventing means via the rotating side sealing member. At the same time, the sliding heat generated in the rotating ring can be radiated to the power transmission mechanism of the compressor via the outside air or the drive shaft.

  In particular, according to the invention described in claim 10, the position on the radial side of the inner peripheral surface where the second seal member of the annular step portion is hermetically abutted is compressed more than the outer peripheral side edge of the sliding surface. By adopting the center side of the machine, it is possible to prevent early wear of the sliding protrusion due to excessive pressure on the sliding surface, and at the same time, the inner peripheral surface where the second seal member of the annular step portion is hermetically contacted Refrigerant leakage due to excessive sliding surface pressure can be prevented by setting the radial side position to the outside of the compressor with respect to the inner peripheral edge of the sliding surface.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a piston reciprocating swash plate compressor 1 is shown as an example of a compressor 1 to which the present invention is used. The compressor 1 constitutes a part of a refrigeration cycle using, for example, CO ₂ (carbon dioxide) as a refrigerant. That is, the compressor 1 compresses the low-temperature and low-pressure CO ₂ refrigerant by an evaporator (not shown) to increase the temperature and pressure, and sends the compressed CO ₂ refrigerant to a cooler (not shown).

  The configuration of the compressor 1 will be described. The cylinder block 3, the rear head 6 assembled on the rear side (right side in FIG. 1) of the cylinder block 3 via the valve plate 5, and the cylinder block 3 are accommodated. Thus, the front head 4 fixed to the front side (the left side in FIG. 1) of the rear head 6 and the drive shaft 7 are provided, and the front head 4 and the rear head 6 are provided with fastening bolts 8 and 8 for a cylinder bore 11 described later. The substantially cylindrical housing 2 is configured by being inserted and fixed to each other along the axial direction. The cylinder block 3 is fixed to the rear head 6 by fastening means (not shown).

  A crank chamber 9 is defined by the front head 4 and the cylinder block 3. The crank chamber 9 houses a drive shaft 7 whose one end projects from the front head 4 and to which a power transmission member (not shown) such as a pulley is fixed. One end side of the drive shaft 7 is provided so as to pass through a boss portion 4 a that protrudes outward from the center portion of the front head 4.

  Further, the front end side of the drive shaft 7 is hermetically sealed with the front head 4 through a mechanical seal 10 provided between the front shaft 4 and a thrust flange that is externally provided on the outer peripheral surface. 12, a radial bearing 13 provided on the inner surface of the boss portion 4a and a thrust bearing 14 provided on the inner surface of the front head 4 are rotatably supported. The rear end side of the drive shaft 7 is rotatably supported via a radial bearing 16 housed in the support recess 15 of the cylinder block 3. The detailed configuration of the mechanical seal 10 will be described later.

  The cylinder block 3 is formed with the support recess 15 that supports the drive shaft 7 and a plurality of cylinder bores 11 that are arranged at equal intervals on a circumference centered on the support recess 15. A single-head piston 18 is inserted into each cylinder bore 11 so as to be able to reciprocate.

  The swash plate 19 is formed in a columnar shape having a predetermined thickness. The swash plate 19 is centered on a support shaft 21 inserted in a long hole 20 formed in the drive shaft 7 in the axial direction of the drive shaft 7. The pin 22 is attached so as to be tiltable, and a pin 22 protruding from the drive shaft 7 is engaged with the longitudinal hole 23 of the swash plate 19 so as to rotate integrally with the rotation of the drive shaft 7. . A tail portion 18 a of a single-head piston 18 projecting into the crank chamber 9 via a pair of shoes 24 is moored at the peripheral portion of the swash plate 19.

  Therefore, when the drive shaft 7 rotates, the swash plate 19 rotates integrally with the rotation of the drive shaft 7, and this rotational motion is converted into the reciprocating linear motion of the single-headed piston 18 via the shoe 24. The volume of the compression chamber 26 formed between the piston 18 and the valve plate 5 in the cylinder bore 11 is changed.

  A storage space 27 extending in the axial direction over the front and rear of the support shaft 21 is formed inside the drive shaft 7. The storage space 27 is formed by opening a cylinder block 3 side end of the drive shaft 7 and forming a bottomed cylinder with a bottom 7a formed at the opposite end thereof. It is located from the 3 side to the vicinity facing the boss 4a of the front head 4.

  In this storage space 27, a sliding member 28 through which the support shaft 21 passes, and an elastic biasing force from the front head 4 side to the sliding member 28 are elastically mounted between the sliding member 28 and the bottom portion 7a. Is provided between the sliding member 28 and the spring receiver 30 provided in the vicinity of the opening of the drive shaft 7 so that the sliding member 28 is axially viewed from the cylinder block 3 side. A stroking spring 31 for applying an urging force is accommodated.

  The rear head 6 is joined to the cylinder block 3 via the valve plate 5 to define a suction chamber 33 and a discharge chamber 34 continuously formed around the suction chamber 33. Further, the valve plate 5 has a suction hole 35 that communicates the suction chamber 33 and the compression chamber 26 via a suction valve (not shown), and a discharge that communicates the discharge chamber 34 and the compression chamber 26 via a suction valve (not shown). A hole 36 is formed. The rear head 6 is equipped with a pressure control valve (not shown) to control the communication state between the discharge chamber 34 and the crank chamber 9 and the communication state between the crank chamber 9 and the suction chamber 33 to control the crank chamber pressure. It is supposed to be.

  Therefore, when the drive shaft 7 rotates, the rotational force is transmitted to the swash plate 19 via the support shaft 21, and the swash plate 19 rotates and the piston 18 reciprocates in the cylinder bore 11. In the downward stroke, the working fluid in the suction chamber 33 is sucked into the compression chamber 26 through the suction hole 35, and in the upward stroke of the piston 18, the working fluid in the compression chamber 26 is compressed and discharged through the discharge hole 36. It will be discharged into the chamber 34.

  When the crank chamber pressure is reduced by the pressure control valve, the moment in the stroke increasing direction caused by the pressure difference between the crank chamber pressure and the back pressure (compression chamber pressure) of the piston 18 increases, and the spring of the destroking spring 29 is increased. The swash plate 19 moves to the front head 4 side against the force, the swash plate 19 rotates around the head of the pin 22 and the inclination angle of the swash plate 19 with respect to the plane perpendicular to the drive shaft 7 increases. The piston stroke increases and the discharge capacity increases. On the other hand, when the crank chamber pressure is increased, the moment in the stroke decreasing direction caused by the pressure difference between the crank chamber pressure and the back pressure (compression chamber pressure) of the piston 18 increases, and the spring force of the stroking spring 31 is resisted. Then, the swash plate 19 moves to the cylinder block 3 side, the swash plate 19 rotates around the head of the pin 22, the inclination angle of the swash plate 19 decreases, the piston stroke decreases, and the discharge capacity decreases. .

  By the way, the mechanical seal 10 includes a rotary ring 40 that rotates integrally with the drive shaft 7, and an annular step of the housing 2 on the opposite side of the axial direction of the drive shaft 7 from the outside air side with respect to the rotary ring 40. The non-rotating fixed ring 41 is held by the portion 42.

  The rotary ring 40 and the fixed ring 41 face each other in parallel along the axial direction of the drive shaft 7, and the opposed side surfaces are in close contact with each other to form a sliding surface, thereby fulfilling a shaft sealing function. However, in the embodiment of FIG. 2, a sliding protrusion 44 is formed to project from the rotating ring 40 toward the fixed ring 41, and the opposing side surface of the sliding protrusion 44 and the opposing side surface of the fixed ring 41 make relative contact. A sliding surface S having a small area is formed. In this embodiment, the sliding protrusion 44 is made of a self-lubricating sliding material, the stationary ring 41 on the opposite side is relatively hard, and the groove 43 is formed on the opposite side surface. Has been. For example, a material such as ceramics may be used for the opposite side surface of the fixed ring 41 facing the sliding protrusion 44.

  Thus, sliding is performed on the opposite side surface of the non-projecting portion of the rotating ring 40, the surface along the protruding direction of the sliding protrusion 44, and the opposite side surface of the fixed ring 41 and the surface along the axial direction of the drive shaft 7. An annular oil storage space 45 for storing lubricating oil to be supplied to the surface S is defined on the inner side (the drive shaft 7 side) than the sliding surface S. The annular step portion 42 slides the position on the radial side of the inner peripheral surface with which the fixed-side seal member 57 comes into airtight contact with the center side of the compressor 1 with respect to the outer peripheral side edge of the sliding surface S. The position is located outside the compressor 1 with respect to the inner peripheral side edge of the moving surface S. Therefore, it is possible to prevent early wear of the sliding protrusion 44 due to the excessive surface pressure of the sliding surface S, and it is also possible to prevent refrigerant leakage due to the excessive surface pressure of the sliding surface S.

  On the other hand, in the compressor 1 according to the present invention, an oil separator (not shown) is attached to the rear head 6 so that oil mixed in the discharged refrigerant gas discharged into the discharge chamber 34 can be separated. The oil is once sent to the oil reservoir chamber 58, further sent from the oil reservoir chamber 58 through the passage 48 into the accommodation space 27 in the drive shaft 7, and then the oil circulation reaching the first oil supply passage 46. Have a route. The first oil supply passage 46 extends from the accommodation space 27 toward the distal end side in the axial direction of the drive shaft 7, and then extends in the radial direction of the drive shaft 7 in the vicinity of the bottom portion 7 a, so It has become an opening. The opening end of the first oil supply passage 46 on the bottom 7 a side is directly connected to the oil storage space 45.

  In the compressor 1 according to the present invention, the fixed ring 41 is disposed on the crank chamber 9 side inside the compressor in the mechanical seal 10, and the fixed ring 41 and the drive shaft 7 are fixed. Based on the fact that there is no need, a gap with a predetermined width can be formed between the fixed ring 41 and the drive shaft 7. One end of this gap communicates with the crank chamber side of the oil storage space 45, and the other A second oil supply passage 47 constituting a part of the oil circulation path is formed by communicating the end side with the crank chamber 9 via a clearance in the radial bearing 13. The predetermined width can be set as appropriate, but is preferably about 1 mm if the flowability of the second oil supply passage 47 is taken into consideration, and is preferably 20 μm to 200 μm if the oil retention during operation stop is taken into consideration.

  As a result, an oil suction force is generated by relatively lowering the crank chamber pressure as described above with a pressure control valve (not shown), so that the oil separated by the oil separator passes through at least the first oil supply passage 46. To the oil storage space 45, and after being temporarily stored in the oil storage space 45, a route that reaches the crank chamber 9 through the second oil supply passage 47 is obtained.

  However, according to this configuration, since the oil storage space 45 serves as a trap and the groove 43 is formed on the opposite side surface of the sliding projection 44, a certain amount of oil is retained even when the compressor 1 is stopped. Since it is held in the housing space 45 and the sliding surface S, there is no shortage of lubricating oil in the sliding surface S even at the initial operation of the compressor 1. Further, when the compressor 1 is operated, oil is automatically supplied from the oil storage space 45 to the sliding surface S by centrifugal force, so that it is necessary to provide a special mechanism for supplying oil to the sliding surface S. Absent.

  Further, since the oil storage space 45 forms a part of the oil circulation path, oil is always supplied to the oil storage space 45 from the first oil supply passage 46 and excess oil is supplied to the second oil supply passage 47. It is sent to the crank chamber 9 side. For this reason, since the oil is separated from the oil circulation path, a problem that the oil is not sufficiently sent to the oil accommodating space 45 does not occur. Further, since a large amount of oil stays in the oil storage space 45, it is possible to avoid a situation in which the oil becomes high temperature during the high speed operation of the compressor 1 and oil sludge is generated in the vicinity of the sliding surface S. Since the amount of oil in the oil storage space 45 does not become excessive, it is possible to prevent blisters from occurring on the sliding surface S connected to the oil storage space 45. Furthermore, even if oil leaks outside through the clearance of the sliding surface S, it is eliminated in the direction away from the sliding surface S due to the centrifugal force during operation of the compressor 1, so that the oil near the sliding surface S Generation of sludge can be prevented.

  In this embodiment, as shown in FIG. 2A, a part of the rotary ring 40 on the drive shaft 7 side is cut out, and an annular rotary side seal is formed in a space 49 formed by the cutout. A member 50 is interposed. In FIG. 2 (b), the rotation side seal member 50 is an independent member made of an elastomer material 50a and is formed in a cylindrical shape. But the structure of this rotation side sealing member 50 is not limited to what is shown by FIG.2 (b). As shown in FIG. 2 (c), the rotation side seal member 50 is basically composed of a single elastomer material 50a as in FIG. 2 (b), but is opposite to the drive shaft side surface and drive shaft. One or more annular bulges 50c may be provided on both sides or one side of the side surface (in FIG. 2 (c), three bulges are provided on each side). Moreover, although not shown, the cross-sectional shape of the rotation-side seal member 50 can be a circle, an ellipse, a rectangle, an X-shape, or the like. Further, although not shown, it may be made of an elastomer material that is directly vulcanized and bonded to the rotating ring 40. With such a configuration, the rotating ring 40 can be held by the drive shaft 7 by elastic deformation of the elastomer material 50a, but cannot be completely connected and fixed to the drive shaft 7. Therefore, the rotation-side seal member 50 enables the rotation ring 40 to move in the axial direction.

  Further, as a reinforcing member for the rotary ring 40, a support member 51 is mounted on the drive shaft 7 on the axial outside air side of the rotary ring 40. The support member 51 is a backup ring for preventing the pushing force of the rotating ring 40 due to the internal pressure of the compressor from being transmitted to the removal preventing means via the rotating side seal member 50. The support member 51 also has a function of quickly radiating the sliding heat generated in the rotating ring 40 to the power transmission mechanism through the outside air or the drive shaft 7.

  Further, as a means for preventing the rotation ring 40 and the support member 51 from coming out of the drive shaft 7 on the outer side in the axial direction from the support member 51, FIGS. A snap ring 52 is fitted. Thereby, contrary to the prior art, even if the rotating ring 40 is arranged on the outside air side of the drive shaft 7 with respect to the fixed ring 41, there is no problem that the rotating ring 40 falls off from the drive shaft 7. In addition, in the case of such a configuration having the prevention means, the rotary ring 40 is biased by the internal pressure of the compressor 1 with the support member 51 interposed between the snap ring 52 and the rotary ring 40 is Even if the drive shaft 7 is not completely connected and fixed, the drive shaft 7 can rotate in unison with the drive shaft 7.

  The fixed ring 41 is a cylindrical body 41a having a collar portion 41b on the rotating ring side, and is attached to the annular stepped portion 42 via the fixed-side seal member 57 so as to be movable to some extent in the axial direction of the drive shaft 7. And is not completely connected to the housing 2. A retainer 55 having a substantially L-shaped cross section is attached so as to be in contact with the vertical surface of the annular step portion 42, and an elastic member such as a spring is formed in a space defined by the retainer 55 and the flange portion 41b. By having an elastic mechanism including 56, the fixed ring 41 is always urged toward the rotating ring by the collar 41b being pressed by the elastic member 56.

  For this reason, the rotating ring 40 is urged toward the removal preventing means as described above, and even if the rotating ring 40 moves to the removal preventing means side, the stationary ring 41 is also moved by the movement of the rotating ring 40. Since it moves, the opposing side surfaces of the stationary ring 41 and the rotating ring 40 are in close contact with each other, and the state where the sliding surface S is formed can be maintained. Therefore, even when the internal pressure becomes higher than the external pressure, it is possible to avoid a large amount of oil leaking from the oil accommodating space 45 through the sliding surface S toward the outside of the compressor 1. In addition, although not shown in the figure, the rotation of the fixed ring 41 with the rotary ring 40 is not possible to rotate relative to the housing 2 due to the shape of the retainer 55, and at the same time, the collar portion 41b of the fixed ring 41 has the retainer 55. This is because the relative rotation is impossible.

  However, the slip-off preventing means is not limited to the snap ring 52, but a metal ring 53 that is press-fitted and fixed to the drive shaft 7 as shown in FIG. 3, and a lock nut fastened to the drive shaft 7 shown in FIG. 54 or a driving force transmission member for transmitting a driving force from a driving source (for example, an engine) to the driving shaft 7 such as an armature or a hub fastened to the driving shaft 7 (not shown). In addition, about the structure similar to FIG. 2 among the structures of the mechanical seal 10 of FIG. 3, FIG. 6, the same code | symbol was attached | subjected and the description was abbreviate | omitted.

  As a result, the rotary ring 40 is urged by the internal pressure of the compressor 1 to the metal ring 53, the lock nut 54, or the driving force transmission member via the support member 51 or directly, so that it is the same as the snap ring 52. In addition, the rotary ring 40 can rotate in synchronization with the drive shaft 7 even if it is not completely connected to the drive shaft 7. When the metal ring 53 is used, the rotating ring 40 can be prevented from coming off, and at the same time, the rotating ring 40 can be reinforced and radiated, so that the support member can be omitted and the number of parts can be reduced. It is.

  Further, the sliding protrusion 44 is not limited to the configuration formed on the rotating ring 40 side as shown in FIG. 2A and FIG. 3, FIG. 5, and FIG. As shown, it may be formed on the fixed ring 41 side. In addition, also about the structure of the mechanical seal 10 of FIG. 4, about the structure similar to FIG. 2, the same code | symbol was attached | subjected and the description was abbreviate | omitted.

  Further, as described above, the elastic mechanism that applies the urging force toward the rotating ring 40 with respect to the fixed ring 41 is mounted with the retainer 55 having a substantially L-shaped cross section so as to contact the vertical surface of the annular stepped portion 42. However, the present invention is not limited to a structure in which an elastic member 56 such as a spring is interposed in a space defined by the retainer 55 and the collar portion 41b. That is, as shown in FIG. 5, the annular stepped portion 42 is provided with a convex portion facing the opposite end of the cylindrical body 41 a of the fixed ring 41, and the cage 55 extends in the axial direction of the drive shaft 7. The drive shaft 7 is L-shaped with a portion extending in the radial direction, the portion extending in the axial direction of the drive shaft 7 is in contact with the inner peripheral surface of the fixed ring 41, and the portion extending in the axial direction of the drive shaft 7 is the fixed ring 41. A space may be defined by interposing between the annular step portion 42 and the convex portion, and a spring 60 as an elastic member may be interposed in the space. Furthermore, as shown in FIG. 6, an O-ring 61, which is an elastic member that also serves as a fixed-side seal member, may be interposed instead of the spring 60. Thereby, since the spring 60 and the O-ring 61 press the cylindrical body 41a of the stationary ring 41, the stationary ring 41 is always urged toward the rotating ring side, so that the same effect as the elastic mechanism of FIG. 2 is obtained. be able to.

  And as FIG. 6 shows, for example, the surface which faces the outer surface of the sliding projection 44 of the rotating ring 40 and the outer surface of the rotating ring sliding projection of the fixed ring 41 is directed outward. You may make it form the oil discharge part 63 by making it expand. As a result, even if oil leaks from the clearance of the sliding surface S, it is discharged to a position away from the sliding surface S by the oil discharge portion 63, so that oil sludge is generated and accumulated in the vicinity of the sliding surface S. Can be prevented. The leaked oil is discharged out of the compressor through an oil discharge hole 64 provided on the lower side of the boss portion 4a in the direction of gravity.

  Finally, the compressor in which the present invention is used has been described as a piston reciprocating variable displacement compressor 1 with reference to FIG. 1, but is not necessarily limited to this type of compressor. Since the mechanical seal 10 including the rotating ring 40 and the fixed ring 41 described above can be interposed, the present invention can be used with any compressor.

FIG. 1 is a cross-sectional view showing an overall configuration of an example of a compressor in which the present invention is used. FIG. 2A is an enlarged cross-sectional view of the main part in the vicinity of the mechanical seal of the above-described compressor, FIG. 2B is an enlarged cross-sectional view of the first seal member, and FIG. It is an enlarged step view of the modification of another 1st seal member. FIG. 3 is an enlarged cross-sectional view of a main part showing another embodiment in which a metal ring is mounted on the outside air side as a prevention means and a rotating ring reinforcing means. FIG. 4 is an enlarged cross-sectional view of a main part showing another embodiment in which the sliding protrusion is provided not on the fixed ring but on the rotating ring side. FIG. 5 is an enlarged cross-sectional view of a main part showing another embodiment in which an elastic mechanism and a holding part are arranged between the fixed ring and the annular step part. FIG. 6 is an enlarged cross-sectional view of a main part showing another embodiment in which a structure for facilitating the discharge of leaked oil and prevention of oil sludge accumulation near the sliding surface is formed on the rotating ring and the stationary ring. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Housing 7 Drive shaft 9 Crank chamber 10 Mechanical seal 40 Rotating ring 41 Fixed ring 42 Annular step part 44 Sliding protrusion 45 Oil accommodation space 46 1st oil supply path 47 2nd oil supply path 50 Rotation side Seal member (first seal member)
50a Elastomer material 51 Support member 52 Snap ring (detachment prevention means)
53 Metal ring (prevention means)
54 Lock nut (prevention means)
55 Cage 56 Elastic member (elastic mechanism)
57 Fixed-side seal member (second seal member)
60 Spring (elastic mechanism)
61 O-ring (elastic mechanism)
S Sliding surface

Claims (10)

A rotating ring that rotates integrally with the drive shaft of the compressor, and a non-rotation fixed by being held in the housing of the compressor on the opposite side to the outside of the axial direction of the drive shaft with respect to the rotating ring Having a ring,
The rotating ring and the stationary ring are a sliding formed by an opposing side surface of the sliding projection protruding from at least one of the rotating ring and the stationary ring and an opposing side surface having no sliding projection. In close contact with the moving surface,
An oil storage space is defined on the inner side of the sliding surface on the rotating ring, the fixed ring, the sliding protrusion, and the side surface of the driving shaft, and a first oil supply passage is provided in the driving shaft. By opening at least one end of the oil supply passage into the oil storage space and further forming a second oil supply passage between the stationary ring and the drive shaft, the oil storage space is formed in the housing. A mechanical seal structure for a compressor, which communicates with a crank chamber defined in the above and forms part of an oil circulation path. A first seal member is interposed between the rotary ring and the drive shaft. On the outside air side of the drive shaft in the axial direction with respect to the rotary ring, a means for preventing the rotary ring from dropping is provided. The mechanical seal structure for a compressor according to claim 1, wherein the mechanical seal structure is fitted to a drive shaft. The fixed ring is held by an annular step portion provided in the housing via a second seal member, and is urged toward the rotating ring by an urging force of an elastic mechanism. A mechanical seal structure of the compressor according to 1 or 2. The elastic mechanism defines a space by the retainer and the stationary ring that are formed of a portion in contact with the annular step portion and a portion extending in the axial direction of the drive shaft, and an elastic member is interposed in the space. It is comprised, The mechanical seal structure of the compressor of Claim 3 characterized by the above-mentioned. The mechanical seal structure for a compressor according to any one of claims 2 to 4, wherein the dropout prevention means is a snap ring. The mechanical seal structure for a compressor according to any one of claims 2 to 4, wherein the drop-off prevention means is a metal ring press-fitted and fixed to the drive shaft. The mechanical seal structure for a compressor according to any one of claims 2 to 4, wherein the drop-off prevention means is a lock nut fastened to the drive shaft. The mechanical seal structure for a compressor according to any one of claims 1 to 7, wherein a support member is mounted on the drive shaft outside in the axial direction from the rotating ring. The support member is a reinforcing member for preventing the pushing force of the rotating ring due to the internal pressure of the compressor from being transmitted to the drop prevention means via the rotating side seal member, and the sliding member generated in the rotating ring. The mechanical seal structure for a compressor according to claim 8, wherein the mechanical seal structure is a heat radiating member for radiating dynamic heat to the power transmission mechanism of the compressor via outside air or a drive shaft. The annular stepped portion has a radial position on the inner peripheral surface with which the second seal member is hermetically abutted, closer to the center of the compressor than the outer peripheral edge of the sliding surface, and The mechanical seal structure for a compressor according to any one of claims 3 to 9, wherein the mechanical seal structure is located outside the compressor with respect to an inner peripheral edge of the sliding surface.

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