JP2008115768A - Oil return structure for compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil return structure for a compressor enabling a part or a whole body of an axial seal part to be easily dipped in oil or immersed in residing oil without great scale structure change, and capable of greatly improving lubricity and air-tightness of the axial seal part. <P>SOLUTION: In the oil return structure for the compressor, an oil separator separating oil in delivery gas from the compressor, and an oil return path returning part of oil separated by the oil separator to a connection port of the compressor via a valve or the like are provided, the connection port is positioned above the axial seal part of the compressor, and positional relation of the connection port and the axial seal part or the oil pocket part is laid out to drop oil returned into the compressor via the connection port on the axial seal part or to introduce the same to the oil pocket part arranged adjacently to the axial seal part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an oil return structure for a compressor, and more particularly to an oil return structure for a compressor that can properly and sufficiently lubricate a shaft seal portion of the compressor.

In a compressor, for example, a well-known compressor as shown in FIG. 10 of Patent Document 1, the gas compressed and discharged by the compressor generally contains oil (lubricating oil). The oil discharged from the compressor together with the gas was separated by an oil separator, and then entered the suction line side to the compressor through an orifice tube or the like, and returned to the compressor in a mist state again. Therefore, the shaft seal part of the compressor, particularly the shaft seal part that penetrates the drive shaft and seals between the inside and the outside of the compressor is not immersed in oil, is not forced lubrication, and is not lubricated. Relied solely on oil mist in the inhaled gas.
Japanese Patent Laid-Open No. 11-182460

  However, in the conventional structure as described above, since the lubrication of the shaft seal portion relies on the oil mist in the intake gas, there remains a problem that the lubricity and airtightness are unstable. Moreover, when the compressor is left without being operated for a long time, the problem that the oil film on the sliding surface in the shaft seal portion becomes unstable becomes unstable.

  Accordingly, an object of the present invention is to make it possible to immerse a part or the whole of the shaft seal part in oil or to immerse it in the accumulated oil without making a significant structural change. An object of the present invention is to provide an oil return structure for a compressor capable of greatly improving the lubricity and airtightness of the compressor.

  In order to solve the above-described problems, an oil return structure for a compressor according to the present invention includes an oil separator that separates oil in a discharge gas from the compressor, and an orifice tube that partially removes the oil separated by the oil separator. And / or an oil return path that returns to the connection port of the compressor via a valve (for example, an electromagnetic valve or an electromagnetic valve as a pressure reducing valve), and the connection port is positioned above the shaft seal portion of the compressor. And the oil returned into the compressor through the connection port is dropped into the shaft seal portion or introduced into an oil reservoir portion disposed adjacent to the shaft seal portion. The positional relationship between the connection port and the shaft seal portion or the oil reservoir is laid out.

  In such an oil return structure of the compressor according to the present invention, a part of the oil separated by the oil separator is positioned above the shaft seal portion of the compressor via the orifice tube or / and the valve. It is directly returned to the connecting port, and is dropped directly on the shaft seal portion through the connecting port, or returned so as to enter the oil reservoir disposed adjacent to the shaft seal portion. By laying out the oil return line in this way, the shaft seal portion is directly immersed in the dropped oil, or is immersed in the oil in the oil reservoir portion disposed adjacently. Therefore, a sufficient lubrication state that cannot be obtained by the conventional oil mist can be obtained.

  The amount of oil returned to the compressor is preferably controlled via the orifice tube or valve so that oil does not accumulate in the compressor. As a result, an appropriate amount of oil is returned, and an excessive oil return is avoided while maintaining a sufficient lubrication state.

  As a structure for forming the oil reservoir portion, for example, a ring through which the drive shaft of the compressor passes is provided on the compressor inner side of the shaft seal portion (behind the shaft seal portion), and the ring and the shaft seal are formed by the ring. An oil reservoir can be formed at a position adjacent to the shaft seal portion between the two portions. In this case, a seal member may be provided between the ring and the compressor housing or / and between the ring and the drive shaft of the compressor in order to improve the sealing performance. By providing a seal member in addition to such a ring, a weir-like structure that blocks oil at a position adjacent to the shaft seal portion is configured, and the desired structure can be easily obtained without significantly changing the conventional structure. An oil reservoir is formed.

  Further, as a structure for forming the oil reservoir, a ring-shaped balancer is provided on the inner side of the compressor of the shaft seal portion so that the drive shaft of the compressor penetrates and rotates integrally with the drive shaft. It is also possible to employ a structure in which an oil reservoir is formed at a position adjacent to the shaft seal portion between the balancer and the shaft seal portion by providing a seal member between the outer peripheral portion and the compressor housing. it can. That is, instead of a conventional semi-ring balancer, a ring-shaped balancer is provided, and the balancer itself has a function of a weir by sealing between the outer periphery of the balancer and the compressor housing. It is a structure which forms a pool part. Since the outer peripheral portion of the balancer rotates with a slight gap with respect to the compressor housing, a sliding and sealing member corresponding to the rotational movement is provided.

  When the oil reservoir as described above is formed, it is preferable that a breathing hole for equalizing the oil reservoir space and the compressor suction space and for releasing the overflow oil is provided at an appropriate position. When the ring is provided, the ring is fixedly arranged, so that the pressure can be equalized between the oil reservoir and the compressor suction space at an appropriate position of the ring, and the overflow oil in the oil reservoir can be supplied to the compressor suction space. It is sufficient to provide a breathing hole that can escape to the side. Similarly, in the balancer system, it is preferable to provide the above-described breathing hole. However, since the balancer rotates with the drive shaft and the stop position cannot be specified, either the balancer or the drive shaft is located near the center of the drive shaft. Alternatively, both may be provided with breathing holes.

  As described above, according to the oil return structure of the compressor according to the present invention, the shaft seal portion, which is a lubrication-required part, can be simply immersed directly in the returned oil or the oil pool without greatly changing the conventional structure. It is possible to immerse in the oil that has been returned to the appropriate amount and stored, and to achieve a sufficient lubrication state that cannot be obtained by the oil mist method. In addition, the shaft seal is immersed in or immersed in the oil regardless of whether the compressor is in operation or not. The oil film of the seal sliding part can be held, and the stable sealing performance by the shaft seal part is exhibited.

  In addition, by providing a seal member and a breathing hole, the return oil held in the compressor is always kept in an appropriate amount, and a desired lubrication state is secured, and occurrence of problems due to excessive oil accumulation is avoided. .

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an oil return structure of a compressor according to a first embodiment of the present invention. In FIG. 1, 1 is a compressor, 2 is a housing thereof, and 3 is a drive shaft of the compressor 1. The drive shaft 3 is provided with a shaft seal portion 4 that seals between the inner side and the outer side of the compressor 1. In this embodiment, the shaft seal portion 4 is fixed to the housing 2 side. It has a mechanical seal type having a fixed seal 4a and a movable seal 4b provided on the drive shaft 3 side and having a sliding portion therebetween. The compressed gas (for example, compressed refrigerant gas) discharged from the discharge port (not shown) of the compressor 1 contains lubricating oil. The oil is separated from the gas by the oil separator 5, and the oil The separated gas is sent to, for example, a condenser (not shown) in the refrigeration circuit.

  Above the shaft seal portion 4, in the present embodiment, a connection port 6 for returning oil into the compressor 1 is provided immediately above the shaft seal portion 4, and the oil separated by the oil separator 5 is provided. Is returned to the connection port 6 and introduced into the compressor 1 through the connection port 6. Since the connection port 6 is provided directly above the shaft seal portion 4, the returned oil is directly dropped onto the shaft seal portion 4. The oil return path is provided with an electromagnetic valve 7 that can be controlled to reduce pressure, and the oil separated by the oil separator 5 is adjusted in flow rate by the electromagnetic valve 7, and is further connected to the connection port 6 via the tube 8. Is returned to the compressor 1. An orifice tube (not shown) may be provided instead of or together with the electromagnetic valve 7. For example, in the illustrated example, it is possible to arrange an orifice tube in the connection port 6. The oil return amount may be controlled, for example, by opening the electromagnetic valve 7 for a certain time and then closing it. Alternatively, an oil level sensor (not shown) may be provided in the compressor 1 and the solenoid valve 7 may be closed when the oil in the compressor 1 reaches a certain amount.

  In this embodiment, a ring 9 through which the drive shaft 3 penetrates is provided on the compressor inner side of the shaft seal portion 4, and the ring 9 is fixed to the housing 2 side. The ring 9 is disposed closer to the shaft seal portion 4 than the balancer 10 rotated integrally with the drive shaft 3, and is connected to a position adjacent to the shaft seal portion 4 between the ring 9 and the shaft seal portion 4. An oil reservoir 11 is formed in which oil introduced through the port 6 is stored. In order to improve the sealing performance of the oil reservoir 11, a ring is provided between the outer periphery of the ring 9 and the inner periphery of the housing 2 and between the inner periphery of the ring 9 and the outer periphery of the drive shaft 3. Shaped seal members 12 and 13 are respectively disposed. Further, in this embodiment, a breathing hole 14 is provided at a position higher than the center of the drive shaft 3 of the ring 9, and the breathing hole 14 causes the oil reservoir 11 and the compressor inner side (suction space side) to The pressure equalization and the overflow oil in the oil reservoir 11 can be released to the compressor suction space side. Note that reference numeral 15 in FIG. 1 denotes a bearing.

  In the oil return structure of the compressor configured in this way, a part of the oil separated by the oil separator 5 is controlled in flow rate by the electromagnetic valve 7, and the compressor 1 through the tube 8 and the connection port 6. Returned in. In the present embodiment, the oil introduced from the connection port 6 is directly dropped onto the shaft seal portion 4, and then dammed by the ring 9 and collected in an oil reservoir portion 11 formed at a position adjacent to the shaft seal portion 4. It is done. Since the ring 9 is sealed by the seal members 12 and 13 and the breathing hole 14 for releasing the overflow oil in the oil reservoir 11 is provided at a position higher than the center of the drive shaft 3, the ring 9 is sufficient for the oil reservoir 11. An amount of oil is accumulated, and a part or the whole of the shaft seal portion 4 adjacent to the oil reservoir portion 11 is immersed in the oil. Therefore, a sufficient lubrication state that cannot be obtained by oil mist is achieved by a very simple improvement without significant structural change. In addition, since an appropriate amount of oil is always stored in the oil reservoir 11, the stable lubrication state and the oil film holding state of the sliding portion are stably maintained regardless of whether the compressor is operating or stopped. The

  FIG. 2 shows an oil return structure of a compressor according to the second embodiment of the present invention. In this embodiment, the oil reservoir is formed using a balancer. The balancer is not a semi-ring shape, but is constituted by a ring-shaped balancer 21 extending over the entire circumference, and functions as a balancer by changing the thickness in the circumferential direction. A ring-shaped seal member 22 is provided between the outer peripheral portion of the ring-shaped balancer 21 and the compressor housing 2, and the shaft seal portion between the balancer 21 and the shaft seal portion 4 is sealed by the seal member 22. An oil reservoir 23 is formed at a position adjacent to 4. That is, even if a slight gap is formed between the outer peripheral portion of the balancer 21 and the compressor housing 2 due to the rotation of the balancer 21, the oil reservoir 23 is provided in the balancer 21 itself through the seal by the seal member 22. It has the function of a weir to form In addition, a breathing hole 24 for equalizing the oil sump space and the compressor suction space and allowing the overflow oil in the oil sump 23 to escape is located near the center of the drive shaft 3 at the ends of the balancer 21 and the drive shaft 3. It is provided to extend through both. Other configurations are the same as those in the first embodiment.

  In such an oil return structure of the compressor according to the second embodiment, the balancer is configured in the ring-shaped balancer 21 and the seal member 22 is provided between the balancer 21 and the oil using the balancer 21 itself. A reservoir 23 is formed. By providing the breathing hole 24 at an appropriate position, a sufficient amount of oil is stored in the oil reservoir 23, and a part or the whole of the shaft seal portion 4 adjacent to the oil reservoir 23 is immersed in the oil. Will be. Therefore, also in this embodiment, a sufficient lubrication state that cannot be obtained by oil mist is achieved by a very simple improvement without accompanying a significant structural change. In addition, since an appropriate amount of oil is always stored in the oil reservoir 23, a stable lubrication state and an oil film holding state of the sliding portion are stably maintained regardless of whether the compressor is operating or stopped. The

  The oil return structure for a compressor according to the present invention can be applied to virtually any type of compressor including a scroll compressor.

It is a schematic block diagram which shows the oil return structure of the compressor which concerns on the 1st embodiment of this invention. It is a schematic block diagram which shows the oil return structure of the compressor which concerns on the 2nd embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Housing 3 Drive shaft 4 Shaft seal part 4a Fixed seal 4b Movable seal 5 Oil separator 6 Connection port 7 Solenoid valve 8 Tube 9 Ring 10 Balancer 11 Oil reservoir part 12, 13 Seal member 14 Breathing hole 15 Bearing 21 Ring shape Balancer 22 Seal member 23 Oil reservoir 24 Breathing hole

Claims (6)

  An oil separator that separates oil in the gas discharged from the compressor, and an oil return path that returns a part of the oil separated by the oil separator to the connection port of the compressor via an orifice tube or / and a valve The connection port is located above the shaft seal portion of the compressor, and oil returned into the compressor through the connection port is dropped onto the shaft seal portion or adjacent to the shaft seal portion. An oil return structure for a compressor, wherein a positional relationship between the connection port and the shaft seal portion or the oil reservoir portion is laid out so as to be introduced into the oil reservoir portion arranged in a manner.   The oil return structure of the compressor according to claim 1, wherein an oil return amount into the compressor is controlled via the orifice tube or / and a valve.   A ring through which the drive shaft of the compressor passes is provided on the inside of the compressor of the shaft seal portion, and an oil pool is provided at a position adjacent to the shaft seal portion between the ring and the shaft seal portion by the ring. The oil return structure for a compressor according to claim 1 or 2, wherein a portion is formed.   The oil return of the compressor according to claim 3, wherein a seal member is provided between the ring and the compressor housing or / and between the ring and a drive shaft of the compressor for improving the sealing performance. Construction.   A ring-shaped balancer that penetrates the compressor drive shaft and rotates integrally with the drive shaft is provided inside the compressor of the shaft seal portion, and is provided between the outer periphery of the balancer and the compressor housing. The oil return structure for a compressor according to claim 1, wherein an oil reservoir is formed at a position adjacent to the shaft seal portion between the balancer and the shaft seal portion by providing a seal member. .   A breathing hole is provided between the oil reservoir and the compressor suction space, the pressure between which can be equalized, and overflow oil in the oil reservoir can be released to the compressor suction space. The oil return structure of the compressor in any one of 1-5.

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