JP3698175B2 - Shaft seal structure of scroll fluid machine - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement in a shaft seal structure at a discharge port portion on a driven scroll side, particularly when used as an air compressor in an entire-system rotary scroll fluid machine.
[0002]
[Prior art]
The scroll fluid machine creates a closed space by setting up spiral wraps on two scroll end plates, meshing these wraps facing each other, and revolving the scroll relatively. Is a machine that compresses gas by sequentially reducing and moving the scroll from the outer peripheral side of the scroll toward the inner peripheral side.
[0003]
There are two types of the structure of this scroll fluid machine.
One of them consists of a fixed scroll and an orbiting scroll. By rotating the drive shaft of the orbiting scroll surrounded by the housing eccentrically with respect to the fixed scroll fixed to the housing, a closed space is formed in the scroll. It is what you make. In this system, since the discharge port and the suction port are fixedly provided on the fixed scroll side, it is not necessary to seal the rotating shaft as a subject of the present invention.
[0004]
The other one is an object of the present invention, in which the driven scroll shaft is eccentric with respect to the drive scroll shaft, and the driven scroll revolves with respect to the drive scroll via a revolution mechanism. Therefore, the driving scroll and the driven scroll are both rotated. The feature of this structure is that the weight balance of the rotating body is better, the generation of vibration is smaller, the number of parts is smaller, and the structure is simpler than that of the system having the fixed scroll.
[0005]
FIG. 6 is a longitudinal sectional view showing the entire structure of the entire system rotary scroll fluid machine equipped with the conventional shaft seal structure. With reference to FIG. 3, the whole-system rotary scroll fluid machine and its shaft seal structure will be described.
[0006]
In FIG. 6, a drive scroll attachment body (3) for attaching a drive scroll (2) to be described later is fixed to the left end of the drive shaft (1) linked to a motor (not shown). The drive scroll attachment body (3) is provided with an attachment portion (3b) on the outer peripheral side of the shaft tube (3c) for fitting to the drive shaft (1), and the shaft tube (3c) and the attachment portion (3b). An appropriate number of intake holes (3a) for sucking cooling air are provided in between.
[0007]
A ball bearing (4) is fitted to the mounting portion (3b) of the drive scroll mounting body (3). The outer ring of the ball bearing (4) is fixed to a drive scroll housing (6) fixed to the pedestal (5), and the drive scroll mounting body (3) is fixed to the drive shaft (1). The drive scroll housing (6) is rotatably held.
[0008]
On the outer periphery of the drive scroll housing (6), a plurality of vent holes (6a) for releasing the air that has cooled the drive scroll (2) are provided. Further, a holding plate (17) for pressing and holding the outer ring of the ball bearing (4) is attached to the drive scroll housing (6) by bolts (18).
[0009]
Drive scroll (2) is a disc-shaped end plate is basically a provided on the back of (2d) fan blade (2c), which is the inner surface of the end plate (2d) sliding surface (2b) to the stand And a spiral wrap (2a) provided .
[0010]
A concave groove is formed at the tip of the wrap (2a) facing the mating sliding surface, and a self-lubricating seal member (7) such as a fluororesin is fitted into the concave groove. Three fan blades (2c) on the back of the drive scroll (2) are provided radially at an angular interval of 120 °, and the drive scroll has the mounting portion (3b) at the outer end of the fan blade (2c). A mounting body (3) is mounted.
[0011]
Three pairs of eccentric revolution mechanisms (8) are provided at three positions at an angular interval of 120 ° near the outer periphery of the sliding surface (2b) where the lap (2a) is erected in the driving scroll (2). It has been. A driven scroll (9) having a lap (9a) facing the lap (2a) is provided on the sliding surface (9b) via the eccentric revolution mechanism (8).
[0012]
The spiral direction of the wrap (9a) in the driven scroll (9) is opposite to the spiral direction of the wrap (2a) in order to mesh with the wrap (2a) of the drive scroll (2). Further, a discharge hole (9e) connected to a discharge cylinder (9f) for discharging the compressed fluid is provided at the center of rotation. Other than that, it has the same external shape as the drive scroll (2).
[0013]
The tip of the discharge cylinder (9f) is fitted into a discharge cylinder (10c) in a driven scroll mounting body (10) described later. A concave groove is provided at the tip of the lap (9a) facing the mating sliding surface, and this concave groove has a self-lubricating seal member (7 such as fluorine resin as in the drive scroll). ) Is fitted.
[0014]
Further, as in the driving scroll (2), three fan blades (9c) are erected on the back surface of the end plate (9d) of the driven scroll (9) at an angular interval of 120 °. A mounting portion (10b) for mounting a driven scroll mounting body (10) to be described later is provided at the outer end of the fan blade (9c).
[0015]
Near the outer periphery of the sliding surface (9b) of the driven scroll (9), three pairs of eccentric revolution mechanisms (8) are provided at three positions spaced by 120 °, and through these eccentric revolution mechanisms (8). As is well known, the driven scroll (9) orbits with a rotational center eccentric from the rotational center of the drive scroll (2).
[0016]
Wrap the drive scroll (2) Contact and driven scroll (9) (2a) to (9a), so as to surround leaving a predetermined space, the drive scroll (2) and the end plate of the driven scroll (9) (2d) ( A dust seal housing (11) is provided between 9d) .
[0017]
The dust seal housing (11) is made of aluminum die cast having a predetermined thickness, is formed in a donut shape, has a fluid suction port (11a) on the outer peripheral surface, and slides of the driving scroll (2) and the driven scroll (9). Self-lubricating dust seals (11c) and (11b) , such as fluorine-based resin, provided at corresponding positions near the outer periphery of the moving surfaces (2b) and (9b) are respectively driven scroll (2) and driven scroll (9). And the dust seal is completed, and the distance between the end plates (2d) and (9d) of the scrolls ( 2 ) and ( 9 ) is regulated.
[0018]
Oite the position not shown in the vicinity of the outer circumference of the dust seal housing (11), a drive scroll housing (6) therewith and the driven scroll housing facing (13) is pinched by bolts.
[0019]
At the center of the driven scroll mounting body (10) attached to the outer end of the fan blade (9c) on the back side of the driven scroll (9), a discharge cylinder (10c) for discharging compressed fluid to the outside is provided. As described above, the discharge cylinder (9f) of the driven scroll (9) is fitted to the cylinder (10c).
[0020]
Oite outside the emissions cylinder (10c), the driven scroll mounting member (10) comprises three mounting portions of the radial (10b) is provided on the mounting portion (10b), driven scroll (9) Is fixed . Between the discharge tube and (10c) mounting portions and (10b) are three vent cooling air flows (10a) is provided.
[0021]
A ball bearing (12) is fitted to the outer periphery of the driven scroll mounting body (10), and the outer ring of the ball bearing (12) is fixed to the driven scroll housing (13) . Thus, the driven scroll mounting body (10) can rotate integrally with the driven scroll ( 9 ) in the driven scroll housing (13) .
[0022]
On the outer periphery of the driven scroll housing (13), an air discharge hole (13a) for discharging the air that has cooled the driven scroll (9) is provided.
[0023]
The driven scroll housing (13), discharge tube (10c) housing cover for covering (14) is mounted in the driven scroll mounting member (10), the outlet hole of the discharge cylinder in the housing cover (14) (10c) (10d) around the discharge fluid, slave moving scroll (9) of the seal member set to prevent the flow into the back (15) are held with the seal retainer (16).
[0024]
Seal set (15) is to sandwich the washer (15b) with two lip packing having rubber elasticity (15a), it was fitted in a recess formed in the housing cover (14), a lip seal ( 15a) The lip portion is in sliding contact with the outer peripheral portion of the outlet hole (10d) for sealing. In addition, an opening (16a) for discharging the compressed fluid is provided at the center of the seal presser (16).
[0025]
The housing cover (14) is provided with air guide holes (14a), and air flowing from the air guide holes (14a) is driven through the three vent holes (10a) of the driven scroll mounting body (10). flows to the back of the scroll (9), the fan blades (9c), has become so that the discharge from the discharge pores of the driven scroll housing (13) (13a) to the outside.
[0026]
[Problems to be solved by the invention]
In conventional full-based rotary scroll fluid machine as described above, the exit holes of the compressed fluid in the driven scroll mounting member (10) for supporting the driven scroll (9) to revolve (10d), electrically in the housing cover (14) It was found that when the housing cover (14 ) is provided with two lip packings (15a) in order to cut off the atmosphere leading to the pores (14a) , the stability and durability of the seal is difficult.
[0027]
Accordingly, the present invention is to improve the sealing structure of the exit hole portion of the center tip of the driven scroll, that aims to achieve a solution of the above-described subject, the simplification of the structure.
[0028]
[Means for Solving the Problems]
(1) Engage the driven scroll end plate and the driven scroll end plate with the spiral wraps facing each other and revolve the driven scroll with respect to the driven scroll, so that the closed space generated by the rotation of the two is In a full-scale rotary scroll fluid machine that is sequentially reduced and moved to the inner peripheral side to compress and discharge the fluid, it is provided at the center of the driven scroll so as to rotate integrally therewith, A seal cylinder is fitted in an airtight and axially slidable manner to the tip of the discharge cylinder for discharging the pressure fluid discharged from the center of the driven scroll, and the pressure By causing a part of the fluid to act on the seal cylinder, axial thrust is applied to the seal cylinder to prevent the pressure fluid in the discharge cylinder from leaking into the housing at the end surface of the seal cylinder. To manner by pressure contact with the seal plate provided in the housing, it so as to prevent leakage of pressure fluid, further, either the at least contact surfaces of the sealing tube and the sealing plate, the radial In addition, the inclined surface should have a large mutual gap.
[0029]
(2) In the above paragraph (1), the seal cylinder is fitted to the outer surface of the tip of the discharge cylinder so as to be slidable in the axial direction, and the pressure fluid discharged from the discharge cylinder to the inner surface of the seal cylinder A pressure receiving surface that can receive the pressure is provided, and a front end surface of the seal cylinder is brought into contact with a seal plate provided in a pressure fluid discharge opening in the housing.
[0030]
(3) In the above item (1), the seal cylinder is fitted to the inner surface of the tip end portion of the discharge cylinder so as to be slidable in the axial direction, and the pressure of the pressure fluid discharged from the discharge cylinder to the seal cylinder A pressure receiving surface adapted to be received, and a front end surface of the seal cylinder is brought into contact with a seal plate provided in a pressure fluid discharge opening in the housing.
[0031]
(4) In any one of the above items (1) to (3), the seal tube can be rotated integrally with the discharge tube.
[0032]
( 5 ) In the above paragraph (1), the seal plate is fitted on the outer surface of the front end of the discharge tube so as not to come off, and the seal tube is slid in the axial direction on the outer surface of the discharge tube on the outer side in the axial direction. The seal cylinder is pressed against the seal plate by applying an axially inward thrust to the seal cylinder by applying pressure fluid discharged from the discharge cylinder to the outer end surface of the seal cylinder. Let's make it.
[0033]
( 6 ) In any one of the above items (1) to ( 5 ), the seal cylinder is made of a synthetic resin having self-lubricating properties.
[0034]
( 7 ) In any one of the above items (1) to ( 6 ), the seal plate is made of a wear-resistant material obtained by curing a sliding contact surface with the seal cylinder.
[0035]
【Example】
Embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 shows the overall structure of a scroll fluid machine equipped with an embodiment of the shaft seal structure of the present invention. In FIG. 1, the same components as the structure described in FIG. 6 as the conventional example are denoted by the same reference numerals, and detailed description of overlapping parts of the same structure and the reference numerals are omitted. Further, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention only to the description unless otherwise specified. It ’s just the above.
[0036]
Figure 2 is a expansion larger view of the shaft seal portion surrounded by circle A in FIG.
[0037]
The air sucked from the suction port (11a) is sequentially reduced and moved in the inner circumferential direction formed by the driven scroll (9) eccentrically revolving with respect to the drive scroll (2) by the eccentric revolution mechanism (8). Compressed in the closed space, and discharged from the discharge hole (9e) at the center of the end plate (9d) of the driven scroll (9). The compressed air is sent in an airtight state into the discharge tube (10c) at the center of the driven scroll mounting body (10).
[0038]
The distal end portion of the discharge cylinder (10c) of the driven scroll mounting body (10) supported by rotation through a ball bearing (12) fitted to the driven scroll housing (13) surrounding the driven scroll (9) is The straight pipe part (30) has a slightly smaller diameter, and an annular groove (31) is cut out on the outer periphery of the tip part of the straight pipe part (30), and an O-ring is formed in the annular groove (31). (32) is inserted.
[0039]
A large-diameter support hole (34) at the rear of the seal tube (33) protruding forward is slidably fitted to the outer periphery of the front end of the straight tube portion (30), and the rear end of the seal tube (33) A knock pin (36) protruding in the radial direction planted in the straight pipe portion (30) is loosely fitted in the axially long hole (35) opened in the rear portion cut in the portion.
[0040]
Therefore, the seal cylinder (33) can be easily inserted from the front end of the straight pipe section (30) and rotates integrally with the discharge cylinder (10c).
[0041]
Tubular sealing (33) is made of synthetic resin having self-lubricity, resin to withstand temperatures of raising the temperature at compression heat, for example, PTFE polytetrafluoroethylene, PPS (polyphenylene sulfide), PEEK (polyetheretherketone), etc. Further, it is made of a material mixed with a filler for improving lubricity and heat resistance, or a material made of molybran disulfide as a base material.
[0042]
The front part of the inner hole of the seal cylinder (33) has a smaller diameter than the large-diameter support hole (34) at the rear part, but has a larger diameter than the outlet hole (37) in the straight pipe part (30). It is a pore (38), and the boundary between the support hole (34) and the vent hole (38) is an inclined pressure receiving surface (39). Therefore, the pressure fluid flowing through the straight pipe portion (30) can enter between the inclined pressure receiving surface (39) and the front end face of the straight pipe portion (30).
[0043]
The front end surface of the seal cylinder (33) presses the inner surface of the seal presser (16) through a seal plate (40) having a slightly larger diameter.
[0044]
The contact surface (40a) of the seal plate (40) with the seal tube (33) is a flat conical inclined surface that goes away from the seal tube (33) in the radial direction .
[0045]
The same inclination may be given to the contact surface of the seal cylinder (33) with the seal plate (40) , or the contact surface of both.
[0046]
The seal plate (40) is made of a material in which the sliding contact surface is hardened by quenching ceramic or steel, hard plating on metal, etc., and is a mirror-polished polishing contact surface with high wear resistance. It is fixed by press-fitting, driving, or adhesive.
[0047]
With this configuration, the seal cylinder (33) rotates integrally with the straight pipe portion (30), and the inclined pressure receiving surface (39) has a central portion of the straight pipe portion (30) of the driven scroll mounting body (10). Since the pressure of the fluid flowing through the cylinder acts, the seal cylinder (33) always presses the seal retainer (16) via the seal plate (40), and even if the tip of the seal cylinder (33) is worn, A thrust according to the fluid discharge pressure always acts on the seal cylinder (33), and the seal is not damaged for a long time.
[0048]
Therefore, since the diameter of the seal plate (40) is larger than the diameter of the seal cylinder (33), even if there is a slight misalignment during assembly of the driven scroll mounting body (10), it is allowed and hinders operation. Never come.
[0049]
Moreover, the contact surface (40a) with the seal cylinder (33) in the seal plate (40) or the contact surface with the seal plate (40) at the front end of the seal cylinder (33) , or the contact surface of both of them, Since the inclination away from the seal cylinder (33) is given in the radial direction , the sliding contact area is reduced, the mutual contact of the sliding contact surface is accelerated, and the contact state of the sliding contact surface is constant and good. Even if a part of one of the sliding contact surfaces is slightly reduced, a sliding contact state without any trouble can be obtained.
[0050]
In FIG. 3 , the basic principle is the same as that shown in FIGS. 1 and 2 , but on the contrary, the seal cylinder (33) is retracted by the pressure of the discharged fluid, and the end face thereof is sealed plate (40). It is made to press-contact with.
[0051]
A receiving step portion (30a) projecting in the radial direction is formed at the outer peripheral rear portion of the straight pipe portion (30) at the tip of the discharge tube (10c). A large-diameter support hole (41) is formed continuously at the inner end of the opening (16a) in the seal presser (16) integral with the scroll housing (6).
[0052]
In the support hole (41), a seal cylinder (33) having a vent hole (38) having a slightly larger diameter than the opening (16a) has a key (42) fitted to the outer surface thereof, and is non-rotatable and has a shaft. It is slidably fitted in the direction. An O-ring (43) is fitted into an annular groove (41a) formed at a suitable position on the inner surface of the support hole (41), and the seal cylinder (33) is sealed with respect to the support hole (41).
[0053]
A slight gap (44) is provided between the back end of the support hole (41) and the front end surface of the seal cylinder (33).
[0054]
The straight pipe portion (30) is fitted with a seal plate (40), and the seal plate (40) is locked to the receiving step portion (30a).
[0055]
The pressure fluid flowing from the straight pipe portion (30) into the vent hole (38) of the seal cylinder (33) pushes the seal cylinder (33) rearward in the gap (44), and the rear surface of the seal cylinder (33) By pressing the seal plate (40), the pressure fluid protruding from the straight pipe portion (30) is completely prevented from leaking into the housing.
[0056]
FIG. 4 shows still another example, in which the seal tube (33) is fitted in the straight tube portion (30), and the front end surface protruding from the straight tube portion (30) of the seal tube (33) is formed on the scroll housing. The seal retainer (16) of (6) is brought into contact with the seal plate (40) fitted to the rear end of the opening (16a).
[0057]
The inner end of the knock pin (36) provided in the straight pipe portion (30) is locked in the small locking long hole (35) provided in the rear end provided in the rear portion of the seal tube (33).
[0058]
An O-ring (46) is fitted into an annular groove (45) carved on the outer surface of the seal cylinder (33) to seal the straight pipe portion (30).
[0059]
The seal cylinder (33) is pushed outward by the pressure fluid in the straight pipe portion (30) and presses the seal plate (40), so that the pressure fluid does not leak between the housings.
[0060]
【The invention's effect】
Since the seal cylinder that is slidably fitted to the tip of the discharge cylinder that is the rotation center axis of the driven scroll mounting body and the seal plate that receives the seal cylinder pressed by the discharge fluid pressure are sealed, The structure is simplified, and a stable seal with long-term durability can be obtained, and a shaft seal structure that can be easily replaced during assembly or maintenance can be obtained.
[0061]
Further, since the seal cylinder and the seal plate are in sliding contact with each other, the assembly of the scroll fluid machine is facilitated and a shaft seal structure that is not affected by the misalignment at the time of assembling the driven scroll mounting body is obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a scroll fluid machine including an embodiment of a shaft seal structure according to the present invention.
FIG. 2 is an enlarged view of a circle A portion in FIG.
FIG. 3 is a view similar to FIG. 2 showing a different example.
FIG. 4 is a view similar to FIG. 2 showing a different example.
FIG. 5 is a longitudinal side view of a scroll fluid machine having a conventional shaft seal structure.
[Explanation of symbols]
(1) Drive shaft
(2) Drive scroll
(2a) Wrap
(2b) Sliding surface
(2c) Fan blade
(2d) End plate
(3) Drive scroll mounting body
(3a) Air intake hole
(3b) Mounting part
(3c) Shaft cylinder
(4) Ball bearing
(5) Pedestal
(6) Drive scroll housing
(6a) Air vent
(7) Seal member
(8) Eccentric revolution mechanism
(9) Followed scroll
(9a) Wrap
(9b) Sliding surface
(9c) Fan blade
(9d) End plate
(9e) Discharge hole
(9f) Discharge cylinder
(10) Followed scroll mounting body
(10a) Vent
(10b) Mounting part
(10c) Discharge tube
(10d) Outlet hole
(11) Dust seal housing
(11a) Suction port
(11b) (11c) Dust seal
(12) Ball bearing
(13) Driven scroll housing
(13a) Air vent
(14) Housing cover
(14a) Air holes
(15) Seal member set
(15a) Lip packing
(15b) Washer
(16) Seal presser
(16a) Opening
(17) Retaining plate
(18) Bolt
(30) Straight pipe section
(30a) Receiving step
(31) Annular groove
(32) O-ring
(33) Seal cylinder
(34) Support hole
(35) Long hole
(36) Knock pin
(37) Outlet hole
(38) Vent
(39) Inclined pressure receiving surface
(40) Seal plate
(41) Support hole
(41a) Ring groove
(42) key
(43) O-ring
(44) Gap
(45) Ring groove
(46) O-ring
(100) Driven scroll mount
(100e) Non-rotating pin
(100f) O-ring
(100g) Rectangular hole
(101) Shaft seal body
(101a) Discharge hole
(101b) Insertion hole
(102) Shaft seal plate
(103) Shaft seal presser

Claims (7)

The driven scroll end plate and the driven scroll end plate, which are provided with a spiral wrap, are engaged with each other, and the driven scroll is revolved with respect to the driven scroll, so that the closed space generated by the rotation of both is changed from the outer periphery to the inner periphery. In a full-scale rotary scroll fluid machine that is reduced in size to the side and moved to compress and discharge the fluid,
At the center of the driven scroll, a seal cylinder is provided in an airtight manner at the tip of the discharge cylinder that is provided so as to rotate integrally therewith and discharges the pressure fluid discharged from the center of the driven scroll. And by being fitted so as to be slidable in the axial direction, and by causing a part of the pressure fluid to act on the seal cylinder, an axial thrust is applied to the seal cylinder, and the end surface of the seal cylinder is the pressure fluid in the discharge tube is brought into pressure contact with the seal plate provided in the housing so as to prevent the leakage into the housing, it so as to prevent leakage of pressure fluid, further, the seal tube and the seal A shaft seal structure for a scroll fluid machine, wherein at least one of the contact surfaces of the plate is an inclined surface having a large mutual gap in the radial direction .   A pressure-receiving surface that fits the seal cylinder to the outer surface of the tip of the discharge cylinder so as to be slidable in the axial direction, and that can receive the pressure of the pressure fluid discharged from the discharge cylinder on the inner surface of the seal cylinder 2. The shaft seal structure for a scroll fluid machine according to claim 1, wherein a tip end surface of the seal cylinder is brought into contact with a seal plate provided at a pressure fluid discharge opening in the housing.   The seal cylinder is fitted to the inner surface of the tip of the discharge cylinder so as to be slidable in the axial direction, and a pressure receiving surface is provided on the seal cylinder to receive the pressure of the pressure fluid discharged from the discharge cylinder. 2. The shaft seal structure for a scroll fluid machine according to claim 1, wherein the front end surface of the seal cylinder is brought into contact with a seal plate provided in a pressure fluid discharge opening in the housing.   The shaft seal structure for a scroll fluid machine according to any one of claims 1 to 3, wherein the seal cylinder can be rotated integrally with the discharge cylinder.   The seal plate is fitted on the outer surface of the tip of the discharge cylinder while preventing it from coming off, and on the outer side in the axial direction, the seal cylinder is fitted on the outer surface of the discharge cylinder so as to be slidable in the axial direction. A pressure fluid that is discharged more is applied to the outer end surface of the seal cylinder so that an axially inward thrust is applied to the seal cylinder so that the seal cylinder is pressed against the seal plate. Item 2. A shaft seal structure for a scroll fluid machine according to Item 1. The shaft seal structure for a scroll fluid machine according to any one of claims 1 to 5 , wherein the seal cylinder is made of a synthetic resin having self-lubricating properties. The shaft seal structure for a scroll fluid machine according to any one of claims 1 to 6 , wherein the seal plate is made of an abrasion-resistant material in which a sliding contact surface with the seal cylinder is cured.

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