JP3858371B2 - Seal structure of scroll compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seal structure of a scroll compressor such as a scroll vacuum pump used for exhausting an intake system, for example.
[0002]
[Prior art]
This type of scroll-type vacuum pump includes a fixed scroll member having a substrate and a spiral part, and a movable scroll member having a substrate and a spiral part. The compression chamber is formed between the scroll members by meshing the spiral portions. The peripheral wall is provided so as to surround the spiral portion in the substrate of the fixed scroll member. The spiral portion accommodating space is defined by being surrounded by each substrate and the peripheral wall, and is connected to the vacuum intake piping system. Then, by causing the movable scroll member to revolve around the axis of the fixed scroll member, the compression chamber is moved while reducing the volume from the outer peripheral side to the center side of the spiral portion. Accordingly, the gas in the vacuum intake piping system is sucked into the compression chamber through the spiral portion accommodating space, and this intake gas is compressed with the movement of the compression chamber and discharged to the exhaust piping system at the center side of the spiral portion.
[0003]
Here, in order to improve the performance of the vacuum pump, such as lowering the ultimate pressure (representing how low the pressure of the intake system can be reduced), the sealing performance of the spiral housing space is enhanced to increase the air and dust from the outside. It is important to ensure that no inhalation occurs.
[0004]
In general, a dust seal is annularly arranged on the end surface of the peripheral wall and is in contact with the movable scroll member for sealing the spiral housing space. Further, the dust seal is further connected to the outer peripheral side and the inner periphery of the end surface of the peripheral wall. It is also considered to provide a double side. By providing double dust seals, it is possible to seal between the vacuum pressure and the atmospheric pressure in a stepwise manner, and the sealing performance of the spiral housing space is further improved.
[0005]
[Problems to be solved by the invention]
However, when the movable scroll member is inclined with respect to the fixed scroll member for some reason, the movable scroll member tries to be separated from the fixed scroll member in part. Therefore, the contact between the dust seal and the movable scroll member may be cut off at the separated portion, and the sealing performance of the spiral portion accommodating space is deteriorated. As a result, there is a possibility that the predetermined performance of the vacuum pump cannot be exhibited, for example, the ultimate pressure cannot be lowered.
[0006]
However, if both the inner and outer dust seals are strongly pressed against the movable scroll member in order to improve the followability to the tilt of the movable scroll member, wear deterioration due to sliding of both dust seals with the movable scroll member is accelerated. . Therefore, the sealing performance of the spiral housing space is deteriorated early, and the predetermined performance of the vacuum pump cannot be maintained for a long time.
[0007]
The present invention has been made by paying attention to the problems existing in the above-described prior art, and its purpose is to provide a scroll compressor seal excellent in the balance between the followability to the inclination of the movable scroll member and the durability. To provide a structure.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the first aspect of the present invention, the end surface of the peripheral wall or one of the substrates of the other scroll member facing the end surface is provided with a first seal member receiving groove along the extending direction of the peripheral wall. The first seal member receiving groove receives a first seal member that contacts the other end with a tip surface, and the first seal member has a first end on one of the end face of the peripheral wall or the substrate of the other scroll member facing the end face. A second seal member receiving groove is formed in an annular shape along the extending direction of the peripheral wall on the inner peripheral side of the seal member receiving groove, and the second seal member receiving groove is in contact with the other end with a tip surface. 2 seal members are accommodated, and the pressing state of each seal member against the opposing scroll member is set so that the surface pressure of the front end surface of the first seal member is greater than the surface pressure of the front end surface of the second seal member With seal structure .
[0009]
In this configuration, when the movable scroll member is tilted with respect to the fixed scroll member, the front end surfaces of both seal members tend to be separated from the opposing scroll member. In particular, since the first seal member is on the outer peripheral side of the second seal member, the moving amount of the movable scroll member is large, and the first seal member is likely to be separated from the scroll member facing the front end surface.
[0010]
However, the first seal member is biased more strongly than the second seal member toward the opposing scroll member by its own elastic force, and has excellent followability to the tilt of the movable scroll. Therefore, the front end surface of the first seal member is prevented from being separated from the scroll member.
[0011]
Further, the second seal member is weaker than the first seal member in pressing against the scroll member. Therefore, the second seal member is less subject to wear deterioration due to sliding with the scroll member than the first seal member, and the sealing performance of the spiral housing space is not deteriorated at an early stage.
[0012]
According to a second aspect of the present invention, an elastic member is interposed between at least the first seal member of the first seal member and the second seal member and a seal member accommodation groove in which the first seal member is accommodated.
[0013]
In this configuration, when the movable scroll member is inclined with respect to the fixed scroll member, both the seal members try to be separated from the opposing scroll member in part and are further pressed against the opposing scroll member in part. And
[0014]
Accordingly, the side of the seal member that is about to be separated from the opposing scroll member is urged toward the opposing scroll member side by releasing the urging force of the elastic member accumulated by the compression deformation at the time of assembly. Contact with the scroll member is not broken. Further, the side of the seal member that is about to be pressed against the opposing scroll member is allowed to be immersed into the receiving groove due to further compression deformation of the elastic member, and is pressed against the scroll member with an excessive force. There is nothing. Therefore, abnormal wear of the seal member is avoided.
[0015]
According to a third aspect of the present invention, the elastic member has a function of sealing between the seal member in which it is interposed and the seal member receiving groove.
In this configuration, the sealing performance of the spiral housing space is improved.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in a seal structure of a scroll type vacuum pump will be described.
[0017]
As shown in FIG. 1, the front housing 11 is bonded and fixed to a fixed scroll member 12 that also serves as a rear housing. The rotating shaft 13 is rotatably supported by the front housing 11. The eccentric shaft 14 projects from the rotation shaft 13 in the front housing 11. The bearing 15 is fitted on the outer periphery of the eccentric shaft 14.
[0018]
The movable scroll member 16 is fitted to the bearing 15 and supported by the eccentric shaft 14 via the bearing 15 so as to be relatively rotatable. A known regulating mechanism 17 including a crankpin 17 a and the like is interposed between the movable scroll member 16 and the front housing 11. The movable scroll member 16 is restricted from rotating around its own axis by the restriction mechanism 17. Therefore, when the rotary shaft 13 is rotated, the movable scroll member 16 is revolved around the axis of the rotary shaft 13 (the axis of the fixed scroll member 12) via the bearing 15 by the eccentric shaft 14.
[0019]
The fixed scroll member 12 includes a substrate 21 that also serves as an outer shell of the pump, and a spiral portion 22 that is erected on the inner surface of the substrate 21 toward the front housing 11 side. The movable scroll member 16 includes a substrate 23 and a spiral portion 24 erected on the inner surface of the substrate 23 toward the fixed scroll member 12 side. The scroll members 12 and 16 are meshed with each other at the spiral portions 22 and 24, and the end faces 22a and 24a in the axial direction of the spiral portions 22 and 24 are opposed to the inner surfaces of the substrates 23 and 21 of the opposing scroll members 16 and 12, respectively. ing. The compression chamber 25 is surrounded by the spiral portions 22 and 24 and the substrates 21 and 23. When the movable scroll member 16 is revolved around the axis of the rotary shaft 13, the compression chamber 25 is moved while reducing the volume from the outer peripheral side of the spiral toward the central side.
[0020]
A peripheral wall 26 that also serves as an outer shell of the pump is integrally formed on the outer peripheral portion of the substrate 21 of the fixed scroll member 12 so as to surround the spiral portions 22 and 24. An end surface 26 a in the axial direction of the peripheral wall 26 is opposed to the inner surface of the substrate 23 of the movable scroll member 16 on the inner peripheral side. The spiral portion accommodating space 27 is defined by being surrounded by the substrates 21 and 23 and the peripheral wall 26. The suction port 28 is drilled on the outer periphery of the peripheral wall 26, and connects the compression chamber 25 located on the outermost peripheral side of the spiral, that is, in the suction process, to a vacuum suction piping system (not shown) through the spiral portion accommodating space 27. The discharge port 29 is formed at the center of the substrate 21 of the fixed scroll member 12, and opens the compression chamber 25 located at the most central side of the spiral, that is, in the discharge process, to an exhaust pipe system (not shown). Therefore, when the compression chamber 25 moves from the outer peripheral side of the spiral to the center side, the gas in the vacuum intake piping system is sucked into the compression chamber 25 and compressed through the suction port 28 and the spiral portion accommodating space 27. Then, the gas is discharged to the exhaust pipe system through the discharge port 29.
[0021]
Next, the seal structure will be described in detail.
As shown in FIGS. 1 to 3, the tip seal housing groove 31 is formed on the end faces 22 a and 24 a of the spiral portions 22 and 24 so as to extend in the spiral extension direction. The chip seal 32 made of synthetic resin has a spiral shape and is accommodated in each chip seal accommodation groove 31.
[0022]
The first dust seal housing groove 33 is formed in an annular shape so as to extend in the extending direction on the end surface 26 a of the peripheral wall 26. The second dust seal housing groove 34 is formed in a concentric ring shape on the inner peripheral side of the first dust seal housing groove 33 on the end surface 26 a of the peripheral wall 26. The first dust seal 35 made of synthetic resin as the first seal member has a ring shape and is accommodated in the first dust seal accommodation groove 33. The second dust seal 36 made of synthetic resin as the second seal member has a ring shape smaller in diameter than the first dust seal 35 and is accommodated in the second dust seal accommodation groove 34.
[0023]
The packings 37 to 39 made of synthetic rubber as an elastic member have a circular cross section and have a spiral (37) or ring (38, 39) outer shape according to the corresponding chip seal 32 or dust seal 35, 36. The packing 37 is interposed between each chip seal 32 and the chip seal housing groove 31. The packing 38 is interposed between the first dust seal 35 and the first dust seal accommodation groove 33, and the packing 39 is interposed between the second dust seal 36 and the second dust seal accommodation groove 34.
[0024]
Here, the spacing from the inner bottom surfaces 31a, 33a, 34a of the respective housing grooves 31, 33, 34 to the substrates 21, 23 of the opposing scroll members 12, 16 is accommodated in the respective housing grooves 31, 33, 34. The seals 32, 35, and 36 are narrower than the natural height of the packings 37 to 39 plus the natural height. Accordingly, the seals 32, 35, 36 are pressed against the substrates 21, 23 of the opposing scroll members 12, 16 with the front end surfaces 32a, 35a, 36a in a state where both the scroll members 12, 16 are assembled. It becomes a state. In this state, the packing 37 is on the base end surface 32 b of the chip seal 32 and the inner bottom surface 31 a of the chip seal receiving groove 31, and the packing 38 is the base end surface 35 b of the first dust seal 35 and the inner bottom surface 33 a of the first dust seal receiving groove 33. In addition, the packing 39 is in elastic contact with the base end face 36 b of the second dust seal 36 and the inner bottom face 34 a of the second dust seal receiving groove 34.
[0025]
Therefore, the compression chamber 25 is sealed from the other compression chamber 25 and the spiral portion accommodating space 27 by the tip seal 32. Further, the spiral portion accommodating space 27 is sealed from the atmospheric atmosphere in the pump by dust seals 35 and 36. In particular, by providing the dust seals 35 and 36 in a double manner, the space between the vacuum pressure and the atmospheric pressure can be sealed step by step, and the sealing performance of the spiral portion accommodating space 27 is improved.
[0026]
In the present embodiment, the ideal is such that the ratio of the pressure per unit area (surface pressure) acting on the tip surface 35a of the first dust seal 35 and the surface pressure of the tip surface 36a of the second dust seal 36 exceeds 1. Specifically, the pressing state of the first and second dust seals 35 and 36 against the substrate 23 is set to be 1.5 to 2.5. The pressing state is set by the depth of the dust seal receiving grooves 33 and 34, the gap between the end surface 26a of the peripheral wall 26 and the inner surface of the substrate 23 facing it, the material and height of the packings 38 and 39, and the material of the dust seals 35 and 36. It is done by adjusting the height and so on.
[0027]
FIG. 4 shows a test result of measuring the ultimate pressure of the vacuum pump when the surface pressure of the front end surface 36a of the second dust seal 36 is fixed to a certain value and the surface pressure of the front end surface 35a of the first dust seal 35 is changed. It is a graph which shows. When the pressing force of the first dust seal 35 against the substrate 23 is weak and the surface pressure ratio with the tip surface 36a of the second dust seal 36 is low, that is, when the total sealing ability of both the dust seals 35 and 36 is low, the ultimate pressure is lowered. It is not difficult to imagine that this is not possible even before this test.
[0028]
However, from the graph of FIG. 4, the pressing force of the first dust seal 35 against the substrate 23 is increased to set the surface pressure of the front end surface 35 a of the first dust seal 35 high, that is, the total of both dust seals 35 and 36. It can be seen that increasing the sealing ability does not necessarily reduce the ultimate pressure of the vacuum pump. From this, in order to lower the ultimate pressure of the vacuum pump, the present inventor has a balance between the sealing capability of the first dust seal 35 and the sealing capability of the second dust seal 36, that is, the front end surface 35a of the first dust seal 35. It was found that the balance between the surface pressure of the second dust seal 36 and the surface pressure of the tip surface 36a of the second dust seal 36 is important.
[0029]
And when the surface pressure ratio of the front end surface 35a of the first dust seal 35 and the front end surface 36a of the second dust seal 36 is set to 1.5 or more and 2.5 or less, the balance of the sealing ability of both 35 and 36 is good. Thus, the ultimate pressure of the vacuum pump could be reduced to a desired pressure or lower.
[0030]
In this embodiment having the above-described configuration, the following effects can be obtained.
(1) When the movable scroll member 16 is tilted with respect to the fixed scroll member 12 due to blurring of the rotating shaft 13 or the like, the substrate 23 tends to be separated from the dust seals 35 and 36 in part. In particular, since the first dust seal 35 is located farther from the eccentric shaft 14 than the second dust seal 36, the movement amount of the substrate 23 is large, and the tip surface 35a and the substrate 23 are likely to be separated.
[0031]
However, the surface pressure of the front end surface 35 a of the first dust seal 35 is set larger than the surface pressure of the front end surface 36 a of the second dust seal 36. Accordingly, the first dust seal 35 is urged toward the movable scroll member 16 more strongly than the second dust seal 36 by its own elastic force. As a result, the first dust seal 35 is excellent in followability with respect to the inclination of the movable scroll member 16, and the tip end surface 35 a of the first dust seal 35 is prevented from being separated from the substrate 23 and the sealing performance of the spiral portion accommodating space 27 is prevented from being lowered.
[0032]
The second dust seal 36 is pressed against the movable scroll member 16 more weakly than the first dust seal 35. Therefore, the second dust seal 36 is less subject to wear deterioration due to sliding with the movable scroll member 16 than the first dust seal 35, and the total sealing ability of both the seals 35, 36 may be lowered earlier than predetermined. Absent. As a result, the predetermined sealing property of the spiral portion accommodating space 27 can be maintained over a long period of time.
[0033]
As described above, by setting the surface pressure of the front end surface 35a of the first dust seal 35 to be higher than the surface pressure of the front end surface 36a of the second dust seal 36, the balance between the followability with respect to the inclination of the movable scroll member 16 and durability. Excellent seal structure.
[0034]
(2) Due to the inclination of the movable scroll member 16 described above, the substrate 23 tends to be separated from the dust seals 35 and 36 in part and further pressed against the dust seals 35 and 36 in part. In particular, since the first dust seal 35 is located farther from the eccentric shaft 14 than the second dust seal 36, the movement amount of the substrate 23 is large, and the tip surface 35 a is easily separated from the substrate 23 and is excessively large with respect to the substrate 23. It is easy to be pressed.
[0035]
However, the packing 38 is interposed between the first dust seal 35 and the second dust seal housing groove 33. Therefore, the side of the first dust seal 35 on which the substrate 23 is about to be separated is urged toward the substrate 23 side by releasing the urging force of the packing 38 accumulated by the compression deformation at the time of assembly, and the tip end surface 35a is There is no separation from the inner surface of the substrate 23. Further, the side of the first dust seal 35 on which the substrate 23 is further pressed is allowed to be immersed (escape) into the first dust seal receiving groove 33 due to further compression deformation of the packing 38, and the substrate 23 is subjected to excessive force. It will not be pressed. Accordingly, abnormal wear of the first dust seal 35 is avoided.
[0036]
As described above, the packing 38 enhances the followability of the first dust seal 35 with respect to the inclination of the movable scroll member 16, maintains the predetermined sealing performance of the spiral portion accommodating space 27, that is, maintains the high performance of the scroll type vacuum pump. Contributed to.
[0037]
(3) The packing 39 enhances the followability of the second dust seal 36 with respect to the inclination of the movable scroll member 16 in the same manner as the relationship between the packing 38 and the first dust seal 35 described above. Therefore, the packing 39 contributes to maintaining a predetermined sealing property of the spiral portion accommodating space 27, that is, maintaining the high performance of the scroll type vacuum pump.
[0038]
(4) The packing 37 improves the followability of the tip seal 32 with respect to the inclination of the movable scroll member 16 in the same manner as the relationship between the packings 38 and 39 and the dust seals 35 and 36 described above. Therefore, the packing 37 contributes to maintaining a predetermined sealing property of the compression chamber 25, that is, maintaining the high performance of the scroll type vacuum pump.
[0039]
(5) The eccentric shaft 14 that supports the movable scroll member 16 is supported by the rotating shaft 13 only at one end side. That is, the movable scroll member 16 is cantilevered on the rotating shaft 13. Therefore, the rotating shaft 13 is easily shaken by the load of the movable scroll member 16 and the eccentric shaft 14, and the movable scroll member 16 is easily inclined with respect to the fixed scroll member 12. As a result, the problems (1) to (4) described above appear remarkably. It is particularly effective to apply the packings 37 to 39 to the vacuum pump having such a configuration in order to achieve the effect.
[0040]
(6) The packings 37 to 39 are elastically contacted with the base end surfaces 32b, 35b, 36b of the seals 32, 35, 36 and the inner bottom surfaces 31a, 33a, 34a of the receiving grooves 31, 33, 34, respectively. , 35 and 36 and the sealing grooves 31, 33 and 34 have a sealing action. Therefore, the sealing performance of the compression chamber 25 and the spiral portion accommodating space 27 by the respective seals 32, 35, and 36 can be further enhanced, and the ultimate pressure can be further lowered.
[0041]
The following embodiments can be implemented without departing from the spirit of the present invention.
In the above embodiment, the dust seals 35 and 36 are provided in double. However, the dust seals 35 and 36 may be changed to provide triple or quadruple dust seals. In this case, it is most desirable to set the pressing state of each dust seal against the movable scroll member 16 so that the outer surface dust seal has a higher surface pressure on the front end surface. The surface pressure of the dust seal may be larger than the surface pressure of the dust seal on the inner peripheral side.
[0042]
The tip seal 32 is located closer to the eccentric shaft 14 than the dust seals 35 and 36 and can follow the inclination of the movable scroll member 16 to some extent by its own elastic force. Therefore, it is possible to adopt a configuration in which the packing 37 is not interposed between the tip seal 32 and the tip seal receiving groove 31.
[0043]
The second dust seal 36 is located closer to the eccentric shaft 14 than the first dust seal 35, and can follow the inclination of the movable scroll member 16 to some extent by its own elastic force. Therefore, it is possible to adopt a configuration in which the packing 39 is not interposed between the second dust seal 36 and the second dust seal housing groove 34.
[0044]
In the above embodiment, the packings 37 to 39 are changed to the spring material as the same elastic member.
○ Applicable to air-conditioning systems and to be embodied in a scroll-type compressor seal structure for compressing refrigerant gas.
[0045]
A technical idea that can be grasped from the above embodiment will be described.
(1) The seal structure according to claim 2 or 3, wherein the elastic member 39 is also interposed between the second seal member 36 and the second seal member accommodation groove 34.
[0046]
In this way, the followability of the second seal member 36 with respect to the inclination of the movable scroll member 16 can also be improved.
(2) On the end surfaces 22a and 24a of the spiral portions 22 and 24 of the fixed scroll member 12 and the movable scroll member 16, chip seal receiving grooves 31 are formed along the spiral extension direction. The tip seal 32 which seals the compression chamber 25 by contacting the substrates 21 and 23 of the scroll members 12 and 16 facing each other with the front end surface 32a is respectively accommodated. Seal structure.
[0047]
In this way, the sealing performance of the compression chamber 25 is improved.
(3) The seal structure according to (2), wherein an elastic member 37 is interposed between the chip seal 32 and the chip seal housing groove 31.
[0048]
In this way, the followability of the tip seal 32 with respect to the inclination of the movable scroll member 16 can be improved.
[0049]
【The invention's effect】
According to invention of Claim 1 of the said structure, it becomes a seal structure excellent in balance with the followable | trackability with respect to the inclination of a movable scroll member, and durability.
[0050]
According to the second aspect of the present invention, the followability of the seal member with respect to the inclination of the movable scroll member can be enhanced, the predetermined sealability of the spiral portion accommodating space can be maintained, and the high performance of the scroll compressor can be maintained.
[0051]
According to invention of Claim 3, the sealing performance of a spiral part accommodation space can be improved, and the performance of a scroll type compressor is improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a scroll type vacuum pump.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
3A is an enlarged view of main parts in a circle B in FIG. 1, and FIG. 3B is an enlarged view of main parts in a circle C in FIG.
FIG. 4 is a graph showing test results conducted by the present inventors.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 12 ... Fixed scroll member, 16 ... Movable scroll member, 21 ... Substrate which comprises a fixed scroll member, 22 ... Similarly spiral part, 23 ... Substrate which comprises movable scroll member, 24 ... Same spiral part, 25 ... Compression chamber, 26 ... peripheral wall, 26a ... end face of peripheral wall, 27 ... spiral portion accommodating space, 33 ... first dust seal accommodating groove as first seal member accommodating groove, 34 ... second dust seal accommodating groove as second seal member accommodating groove, 35 ... A first dust seal as a first seal member, 35a... A front end surface of the first dust seal, 36... A second dust seal as a second seal member, 35a.

Claims (3)

A fixed scroll member having a substrate and a spiral portion and a movable scroll member having a substrate and a spiral portion are meshed with each other in the spiral portion to form a compression chamber between the scroll members, and in the substrate of one scroll member A peripheral wall is provided so as to surround the spiral part, a spiral part accommodating space is defined by each substrate and the peripheral wall, and the movable scroll member is revolved around the axis of the fixed scroll member, whereby the compression chamber is surrounded by the outer periphery of the spiral part. In the scroll type compressor configured to move from the side to the center side and perform suction of the gas and compression of the sucked gas through the spiral housing space,
A first seal member receiving groove is formed in an annular shape along the extending direction of the peripheral wall on one end surface of the peripheral wall or the other scroll member substrate facing the end surface. The first seal member that contacts with the front end surface is accommodated, and the inner surface of the first seal member accommodating groove on one of the end surface of the peripheral wall or the substrate of the other scroll member facing the end surface is provided with a peripheral wall. A second seal member accommodation groove is formed in an annular shape along the extending direction, and the second seal member accommodation groove contains a second seal member that comes into contact with the other end surface, and the first seal member The seal structure which set the pressing state of each seal member with respect to the scroll member which opposes so that the surface pressure of the front-end | tip surface of this may become larger than the surface pressure of the front-end | tip surface of a 2nd seal member. The seal structure according to claim 1, wherein an elastic member is interposed between at least the first seal member of the first seal member and the second seal member and a seal member accommodation groove in which the first seal member is accommodated. The seal structure according to claim 2, wherein the elastic member has a function of sealing between a seal member in which the elastic member is interposed and a seal member accommodation groove.

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