JP2008095634A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll compressor provided with a means for capturing foreign matter from a low pressure coolant and lubricating oil that flow in, which is capable of suppressing intrusion of foreign matter by taking into account the shapes of a sliding bearing and a sliding surface. <P>SOLUTION: A space 30 is defined between a driving motor 22 for rotating a shaft 23 and a middle housing 29 in a main body casing 21. The space 30 is provided with the foreign matter capturing means for separating refrigeration oil from a sucked coolant and separating foreign matter from the refrigeration oil. Thereby, intrusion of foreign matter to the sliding bearing composed of a movable side sliding plate 27 and a fixed side sliding plate 28 can be suppressed and damage to sliding surfaces of the movable side sliding plate 27 and the fixed side sliding plate 28 can be prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a scroll compressor.

For example, in a compressor, lubricating oil is supplied to the inside in order to properly slide the bearing. As such a compressor, a vertical scroll type compressor is known in which lubricating oil is sucked together with a low-pressure refrigerant from the upper part of the outer housing, and the low-pressure refrigerant and the lubricating oil flow down in the outer housing.
In this scroll type compressor, the lubricating oil is not stored in the outer housing, but is circulated in the refrigeration cycle together with the refrigerant.

The lubricating oil sucked into the outer housing flows down from the electric motor unit for driving the compression mechanism unit to the compression mechanism unit, lubricates the bearings in the compressor, and then is compressed by the compression mechanism unit. It is discharged from the outer housing together with the refrigerant.
According to such a configuration, the supply of the lubricating oil to each bearing can be realized with a simple configuration, and the lubricating oil sucked together with the low-pressure refrigerant is at a low temperature, so that the refrigerant can be efficiently compressed. .

  Patent Document 1 below discloses a scroll compressor in which an oil film pressure generating mechanism is provided on the thrust bearing surface by the orbiting motion of the movable scroll. That is, in this scroll compressor, a plurality of spiral groove bearing mechanisms or a plurality of tapered land bearing mechanisms are formed on the thrust bearing surface that supports the orbiting scroll, or a plurality of thrust bearings that support the orbiting scroll are provided on the thrust bearing surface. A ring-shaped plate material having a spiral groove bearing mechanism or a plurality of tapered land bearing mechanisms is installed.

Japanese Patent Laid-Open No. 8-319959

  However, such a back pressure application structure requires a complicated back pressure introduction path and an oil pump for oil feeding.

Therefore, in order to improve such a problem, the present applicant has proposed a low-pressure dome type scroll compressor 1 having a structure in which the refrigerant separated from the suction refrigerant can be stored in the back of the orbiting scroll (see FIG. 7).
In this scroll type compressor 1, an electric motor unit 3 that rotationally drives the main shaft 2 and a movable member 4 to which the main shaft 2 is connected are operated, so that the refrigerant sucked into the compression chamber 6 through the compression chamber suction unit 5 is supplied. A compression mechanism 7 for compression is provided in the sealed container 8.

The compression mechanism section 7 is disposed below the electric motor section 3 while forming an intermediate intervening chamber 9 with the electric motor section 3. The compression mechanism section 7 assists the rotation of the main shaft 2 and the operation of the movable member 4. Bearing mechanisms 10, 11, 12, and 13 are provided. The bearing mechanisms 10, 11, 12, and 13 are slid by the lubricating oil that is sucked into the sealed container 8 together with the refrigerant and flows down in the sealed container 8 from the motor unit 3 side to the compression mechanism unit 7 side.
The compression mechanism unit 7 is a refrigerant that flows down from the motor unit 3 side through the storage unit 14 that temporarily stores the lubricating oil flowing down from the motor unit 3 side, and the intermediate interposition chamber 9 and the compression chamber suction unit 5. A refrigerant passage 15 through which the oil is passed, an oil storage chamber 16 for storing the lubricating oil in order to inject the lubricating oil temporarily stored in the storage portion 14 to the bearing mechanisms 12, 13, an intermediate intervening chamber 9 and an oil storage chamber 16 and a lubricating oil passage 17 through which the lubricating oil passes.

  The reservoir 14 is provided so as to face the intermediate intervening chamber 9, the lubricating oil passage 17 is provided such that its inlet end 17 a opens to the reservoir 14, and the refrigerant passage 15 has its inlet end 15 a It is provided so as to protrude from the storage part 14 to the electric motor part 3 side.

  In the scroll compressor 1 as described above, as shown in FIG. 8, a single or a plurality of annular grooves 132 a are formed on any one sliding surface of the thrust slide bearing 13 that slideably supports the movable member 4. And a single or a plurality of radial grooves 132b which are formed substantially radially from the inner diameter side of the thrust slide bearing 13 and communicate with the annular groove 132a at the end of the communicating portion with the outermost annular groove 132a. The width L of the sliding plane 131 formed between the annular grooves 132a and between the annular groove 132a and the inner peripheral edge, and between the annular groove 132a and the outer peripheral edge is equal to or greater than the revolution radius R of the movable member 4, and The revolution diameter is 2R or less.

According to such a scroll compressor 1,
(1) By making the width L of the sliding plane 131 equal to or greater than the revolution radius R of the movable member 4, the sliding plane 131 is always secured without slipping away from the mating sliding plane and lubricated to the oil film thickness or more. Oil does not flow out.
(2) By setting the width L of the sliding plane 131 to be equal to or smaller than the revolution diameter 2R of the movable member 4, any point of the sliding plane 131 will reach the annular groove 132a during one revolution, and this annular When returning from the groove 132a to the sliding surface, lubricating oil is replenished to the sliding surface by a fluid wedge action or a drawing action, and a good oil film pressure is always secured on the sliding face.

  For this reason, the thrust sliding members 13a do not slide in contact with each other, and even with the thrust sliding bearing 13 having a simple structure, the sliding (friction) resistance can be greatly reduced and reliable sliding can be obtained. Further, since the thrust sliding member 13a does not separate beyond the oil film thickness, foreign matter does not enter the sliding portion, and high reliability can be obtained against sudden foreign matter mixing. In addition, since heat generation due to the sliding of the thrust sliding bearing 13 is suppressed, the efficiency of the compressor is also improved. Furthermore, the use of the thrust slide bearing 13 can significantly reduce the number of components, and the scroll compressor 1 can be reduced in cost.

  However, since no groove is provided on the outer peripheral side of the thrust sliding member 13a, the refrigerating machine oil passes through a fine gap on the sliding surface. For this reason, when a foreign material mixes, a foreign material accumulates in the groove part of the thrust sliding member 13a, and it becomes easy for a foreign material to enter into a sliding part.

Further, when the thrust sliding member 13a is in an ideal plane contact, the following problems arise when the inner and outer peripheral sides in the width direction rise from the central portion in the width direction and the sliding surface has a concave shape. .
(1) The surface pressure on the inner and outer peripheral sides of the sliding plate is increased, the oil film is easily cut, and the sliding portion is easily damaged. In addition, since the surface pressure is large, the formed oil film is thin, which causes an increase in friction loss (see, for example, FIG. 9. In this case, in order to explain the surface pressure, The case where the fixed plate is brought into contact is shown).
(2) When the sliding plate revolves, the outer and inner peripheral surfaces of the sliding plate do not form an angle at which an oil film can easily be formed with respect to the direction of motion, so that the oil film is difficult to form. Therefore, the sliding surface is easily damaged (see FIGS. 10a and 10b).
(3) When the sliding surface of the sliding bearing is manufactured with a plate as shown in Patent Document 1, there is a problem that the plate is easily warped or deformed and is difficult to be processed into a desired shape.
The present invention has been proposed in order to improve such a problem, and in particular, in a scroll compressor that revolves while moving a movable scroll while supporting a thrust load with a sliding bearing, low pressure refrigerant and lubricating oil flowing in. It is an object of the present invention to provide a scroll compressor capable of suppressing the intrusion of foreign matter by providing means for capturing foreign matter from the surface and considering the shape of the sliding bearing and the shape of the sliding surface.

  In order to solve the above-mentioned problems, in claim 1 of the present invention, the movable scroll (24) is a sliding bearing composed of a movable side sliding plate (27) and a fixed side sliding plate (28). In the scroll compressor (20) that revolves while supporting the thrust load, a space (30) is provided between the drive motor (22) that rotates the shaft (23) and the middle housing (29) in the main casing (21). ), And the space (30) is provided with a foreign matter catching means for separating the refrigerating machine oil from the sucked refrigerant and separating the foreign substance from the refrigerating machine oil, so that the movable side sliding plate (27) is fixed. It is possible to prevent foreign matter from entering the sliding bearing formed of the side sliding plate (28) and to prevent the sliding surfaces of the movable side sliding plate (27) and the fixed side sliding plate (28) from being damaged. This Can.

  In addition, the code | symbol in the parenthesis attached | subjected to each said component and each following described component is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

According to claim 2 of the present invention, the foreign matter capturing means includes a partition plate (32) for guiding the refrigeration oil in the space (30) in a state where the inner wall of the main body casing (21) and the flow path (33) are formed. And the groove portion (35) provided on the upstream side of the flow path (34) that is below the partition plate (32) and reaches the middle housing (29), the refrigerating machine oil is supplied to the partition plate (32). Along the outer periphery, the flow path area increases and the flow velocity decreases.
When the flow velocity is reduced, the foreign matter heavier than the refrigeration oil is deposited below the refrigeration oil.
The foreign matter rides on the flow while precipitating and flows toward the center, but heavy foreign matter is trapped in the groove (35) provided on the upstream side of the flow path (34) of the middle housing (29), and the middle housing (29). It is possible to prevent inflow.

  According to a third aspect of the present invention, the foreign substance trapping means is a foreign substance trapping porous body (37) provided facing the inlet (36a) of the inflow pipe (36) provided on the upper side of the main body casing (21). With this, a part of the refrigerating machine oil mixed in the refrigerant is once held in the porous body (37) and then dropped, but the foreign matter mixed in the refrigerating machine oil is entangled by the porous body (37). be able to.

  According to a fourth aspect of the present invention, the foreign matter trapping means includes a foreign body trapping porous body (37) provided in the space (30), and a flow path is provided so that a refrigerant can pass through the outer peripheral side of the porous body (37). By configuring (42), the flow of the mixture of the refrigerant and the refrigerating machine oil that has flowed from the drive motor (22) side of the upper part of the main body casing (21) is bent toward the outer peripheral side, so that the refrigerating machine oil having a high density is obtained. It collides with the porous body (37) due to inertia, or the refrigeration oil moves to the lower side of the casing and toward the porous body (37) due to gravity due to the specific gravity difference between the refrigerant and the refrigeration oil, and is trapped in the porous body (37). .

According to a fifth aspect of the present invention, the movable sliding plate (27) and the fixed sliding plate (28) are configured so that the sliding surface comes into contact with the sliding surface when no thrust load is applied. Compared to the clearance on the center side in the width direction, the clearance on the outer periphery side and the inner periphery side is made larger, so that when the thrust load is applied, the center portion in the width direction is elastically deformed and the outer periphery side and the inner periphery side Even if the sliding surfaces come into contact with each other, the surface pressure on the inner peripheral side and the outer peripheral side can be made smaller than when the central portion in the width direction is not convex, and an oil film is easily formed.
Furthermore, at the time of start-up, since the movable side sliding plate (27) starts revolving motion with a small thrust load, the inner peripheral end and the outer peripheral end are inclined with respect to the opposing sliding surface, so An oil film is efficiently formed by the wedge effect due to the oil film flowing due to the revolving motion of the sliding surface, and damage to the sliding surface can be avoided reliably from the start.

  According to a sixth aspect of the present invention, the rigidity of the members constituting the fixed side sliding plate (28) is made larger than that of the movable side sliding plate (27), so that the groove is formed on the sliding surface. Warpage and deformation can be prevented when applying.

  Further, according to the seventh aspect of the present invention, even if the refrigeration oil may be lost by forming irregularities on the sliding surface on the fixed-side sliding plate (28) side, sliding on a flat surface without irregularities may occur. If the surface is on the movable side sliding plate (27), an oil film can be formed with the refrigerating machine oil adhering to the flat portion.

Hereinafter, one embodiment of a scroll compressor according to the present invention will be described and described with reference to the accompanying drawings.
FIG. 1 shows a scroll compressor 20 according to a first embodiment of the present invention.
This scroll compressor 20 is substantially the same as the low-pressure dome type scroll compressor 1 having a structure capable of storing the refrigerant separated from the suction refrigerant shown in FIG. Although a detailed description thereof is omitted, the driving motor 22 disposed on the upper side of the main body casing 21 is driven by rotating the shaft 23.
That is, the scroll compressor 20 is configured to revolve the movable scroll 24 by rotating the shaft 23 in the main body casing 21, compress the sucked refrigerant, and discharge the refrigerant outside the main body casing 21. Reference numeral 24 denotes a structure in which a revolving motion is carried out while supporting a thrust load by a sliding bearing composed of a movable side sliding plate 27 and a fixed side sliding plate 28.
Further, in the scroll compressor 20, the shaft 23 revolves the movable scroll 24, and the refrigerant sucked into the working chamber 25 is compressed and discharged from the discharge port 26.
In the scroll compressor 20, since a thrust load acts upward on the movable scroll 24 in FIG. 1, the movable scroll 24 includes a movable side sliding plate 27 and a fixed side sliding plate 28. Revolving motion while supporting the thrust load with a sliding bearing.

  In the scroll compressor 20 configured as described above, the refrigerant flowing from the suction port (not shown) passes through the gap of the drive motor 22 and reaches the space 30 formed between the drive motor 22 and the middle housing 29. Since the flow rate of the refrigerant is slow in this space 30, the refrigeration oil having a high density is separated downward due to the specific gravity difference. Since a large amount of gas-phase refrigerant exists above the space 30, the refrigerant is sucked by the pipe 31 protruding above the space 30.

  The refrigerating machine oil separated downward travels along the partition plate 32, passes through the flow path 33 provided on the outer peripheral side of the partition plate 32, and reaches below the partition plate 32. The partition plate 32 prevents the turbulence caused by the flow from being transmitted below the partition plate 32 and also serves as a guide for the refrigerating machine oil to go to the outer peripheral side.

The refrigerating machine oil that has come below the partition plate 32 flows from the outer peripheral side toward the central axis side, flows from the flow path 34 provided in the middle housing 29 into the inner peripheral side of the middle housing 29, and moves to the movable side sliding plate 27 and fixed. It enters between the plates from the inner peripheral side of the side sliding plate 28 and exerts a lubricating action.
On the other hand, the refrigerating machine oil that has passed between the movable side sliding plate 27 and the fixed side sliding plate 28 merges with the refrigerant that has passed through the pipe 31 and reaches the compressor 20.

Here, the separation of the foreign matter separated from the gas-phase refrigerant together with the refrigerating machine oil will be described.
Since the refrigerating machine oil goes to the outer peripheral side of the partition plate 32, the flow path area increases and the flow velocity decreases.
When the flow velocity is reduced, foreign matters (iron powder, aluminum powder, copper powder, etc.) heavier than the refrigeration oil settle below the refrigeration oil.
The foreign matter rides on the flow while precipitating and flows to the center side. However, the heavy foreign matter is trapped by the groove 35 provided on the upstream side of the flow path 34 of the middle housing 29 and is prevented from flowing into the middle housing 29. be able to.
As a result, it is possible to prevent foreign matter from entering the movable side sliding plate 27 and the fixed side sliding plate 28 and to prevent the sliding surfaces of the movable side sliding plate 27 and the fixed side sliding plate 28 from being damaged. it can.

The scroll compressor 20 concerning this invention can also be comprised as follows as 2nd Embodiment.
That is, in the scroll compressor 20 shown in FIG. 2, a foreign body trapping porous body 37 is provided opposite to the inlet 36 a of the inflow pipe 36 provided at the top of the drive motor 22, and the inflowing refrigerant is supplied to the porous body 37. I try to make it collide.
In this case, the porous body 37 is provided on the support member 40 installed on the holder 39 between the main body casing 21 and the upper casing 38 via the lower surface mesh-shaped cage 41. In addition, the holder | retainer 41 is comprised with the mesh-shaped member.
As the porous body 37, for example, ceramic, a nonwoven fabric made of resin fibers, metal fibers, or the like can be used.

  According to the scroll compressor 20 as described above, a part of the refrigerating machine oil mixed in the refrigerant is once held in the porous body 37 and then dropped, but the foreign material mixed in the refrigerating machine oil is caused by the porous body 37. Can be entangled.

Moreover, the scroll compressor 20 concerning this invention can also be comprised as follows as 3rd Embodiment.
That is, in the scroll compressor 20, as shown in FIG. 3, the foreign body trapping porous body 37 is provided in the space 30 between the drive motor 22 and the compressor 20, and the refrigerant passes through the outer peripheral side of the porous body 37. The flow path 42 can be configured so as to be able to.
In this case, the porous body 37 is provided on the top side of the middle housing 29 via a cage 41 having a lower surface mesh shape.

In the scroll compressor 20 as described above, the flow of the mixture of the refrigerant and the refrigerating machine oil flowing from the drive motor 22 side at the upper part of the main body casing 21 is bent toward the outer peripheral side, so that the refrigerating machine oil having a high density becomes porous due to inertia. The refrigeration oil collides with the body 37, or the refrigeration oil moves to the porous body 37 side under the casing due to gravity due to the difference in specific gravity between the refrigerant and the refrigeration oil, and is trapped in the porous body 37.
The refrigerating machine oil trapped in the porous body 37 is dropped downward, and the foreign matter mixed in the refrigerating machine oil can be entangled by the porous body 37.

Moreover, the scroll compressor 1 concerning this invention can also be comprised as follows as 4th Embodiment.
That is, in this scroll compressor 20, as shown in FIGS. 4 (a) and 4 (b), the movable side sliding plate 27 is planar, and the fixed side sliding plate 28 has the movable side sliding plate. Grooves m are formed at predetermined intervals on the contact surface facing 27.
In FIG. 4 (a), the central portion in the width direction of the fixed-side sliding plate 28 is convex downward compared to the inner and outer peripheral sides. When the thrust load is zero, the central portion in the width direction is mainly used. Molded so that the sliding surface comes into contact. In the drawing, the warp is exaggerated for easy recognition of the convex state, but this warp is actually about several μm to several tens of μm.
On the other hand, in FIG.4 (b), the movable side sliding plate 27 which is a lower plate is made into convex shape.
Although not shown in the drawings, the contact surfaces of the movable side sliding plate 27 and the fixed side sliding plate 28 may be convex.

In the scroll compressor 20 as described above, the central portion in the width direction of the fixed-side sliding plate 28 is protruded downward as compared with the inner and outer peripheral sides, so that the central portion in the width direction is in a state of zero thrust load. It will be in contact.
As a result, even when a thrust load is applied, the center in the width direction is elastically deformed, and even if the sliding surfaces on the outer peripheral side and the inner peripheral side are in contact, the surface pressure on the inner peripheral side and the outer peripheral side is the center in the width direction. Compared with the case where the portion is not convex, the oil film can be easily formed.

  Further, at the time of start-up, since the sliding plate starts revolving motion with a small thrust load, the inner peripheral end and the outer peripheral end are inclined with respect to the opposing sliding surfaces, so that one of the sliding surfaces revolves. By moving, the oil film is efficiently formed by the wedge effect due to the oil film flowing, and damage to the sliding surface can be avoided reliably from the start.

Furthermore, in the scroll compressor 20 concerning this invention, it can also comprise as follows as 5th Embodiment.
In the scroll compressor 20 in this case, as shown in FIG. 5, the thickness of the upper fixed side sliding plate 28 is increased to increase the rigidity. This is because if the plate rigidity is weak, distortion occurs due to the residual stress of the material during groove processing.
Therefore, in this embodiment, the upper fixed side sliding plate 28 is thickened to form an annular block shape (see FIG. 6).
Since the thickness of the fixed sliding plate 28 varies within a tolerance range during processing, a shim for adjusting the tooth tip clearance of the scroll is provided as in the prior art. The fixed side sliding plate 28 is fixed to the middle housing 29 with a pin across the shim.

  Further, the thickness of the upper fixed side sliding plate 28 is increased to form an annular block. The mass increases when the annular block is formed, so that the movable side sliding plate 27 is formed into an annular block. As a result, the mass of the counterweight for achieving dynamic balance increases, and the load on the bearing that supports the shaft 23 that drives the compressor 20 also increases.

Even if the refrigeration oil may be lost in the oil storage part provided on the center side by performing groove processing on the upper fixed side sliding plate 28, the sliding surface on the flat surface without the groove m is on the lower side. If there is, an oil film can be formed with the refrigerating machine oil adhering to the flat portion.
However, when the groove m is provided in the lower movable side sliding plate 27, since the refrigeration oil enters the groove m, it is difficult for the refrigeration oil to be supplied to the sliding surface above the groove m, and an oil film is formed. This is because it becomes difficult, and as a result, the sliding portion is easily damaged.

It is a principal part expanded sectional view concerning 1st Embodiment of the scroll compressor concerning this invention. It is sectional drawing concerning 2nd Embodiment of the scroll compressor concerning this invention. It is a principal part expanded sectional view concerning 3rd Embodiment of the scroll compressor concerning this invention. It is a typical expanded sectional view concerning 4th Embodiment of the sliding bearing in the scroll compressor concerning this invention. It is a typical expanded sectional view concerning 4th Embodiment of the sliding bearing in the scroll compressor concerning this invention. It is a principal part expanded sectional view concerning 5th Embodiment of the scroll compressor concerning this invention. It is a typical expanded sectional view of the sliding bearing in the scroll compressor shown in FIG. It is sectional drawing which shows an example of the conventional scroll compressor. It is a principal part enlarged plan view which shows an example of the sliding surface structure of the thrust slide bearing in the scroll compressor shown in FIG. It is a graph for demonstrating the surface pressure which causes the damage of the sliding surface in a sliding bearing which this invention made the subject. FIG. 10 is a schematic enlarged explanatory view of a sliding surface in the sliding bearing shown in FIG. 9. FIG. 10 is a schematic enlarged explanatory view of a sliding surface in the sliding bearing shown in FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Scroll compressor 21 Main body casing 22 Drive motor 23 Shaft 24 Movable scroll 25 Actuation chamber 26 Discharge port 27, 28 Sliding plate 29 Middle housing 30 Space 31 Pipe 32 Partition plate 33, 34 Flow path 35 Groove part 36 Inflow pipe 36a Inlet 37 porous body 38 upper casing 39 holder 40 strut member 41 cage 42 flow path m groove

Claims (7)

In the main casing (21), the shaft (23) is rotated to cause the movable scroll (24) to revolve, compress the sucked refrigerant, and discharge it outside the main casing (21).
The movable scroll (24) is a scroll compressor (20) that performs a revolving motion while supporting a thrust load with a sliding bearing composed of a movable side sliding plate (27) and a fixed side sliding plate (28).
A space (30) is defined between the drive motor (22) for rotating the shaft (23) and the middle housing (29) in the main casing (21);
A scroll compressor characterized in that, in this space (30), a foreign matter catching means for separating the refrigerating machine oil from the sucked refrigerant and separating the foreign matter from the refrigerating machine oil is provided. The foreign matter catching means includes a partition plate (32) for guiding the refrigerating machine oil in a state where the inner wall of the main body casing (21) and the flow path (33) are formed in the space (30).
The scroll compressor according to claim 1, further comprising a groove (35) provided below the partition plate (32) and upstream of the flow path (34) extending into the middle housing (29). .   The foreign matter capturing means includes a foreign body trapping porous body (37) provided to face an inlet (36a) of an inflow pipe (36) provided on the upper side of the main casing (21). Item 2. The scroll compressor according to Item 1.   The foreign matter trapping means includes a porous body (37) for trapping foreign matter provided in the space (30), and the flow path (42) is configured so that a refrigerant can pass through the outer peripheral side of the porous body (37). The scroll compressor according to claim 1.   When the sliding surface comes into contact with the movable sliding plate (27) and the fixed sliding plate (28) in a state where no thrust load is applied, the clearance on the center side in the width direction of the sliding surface is reduced. 2. The scroll compressor according to claim 1, wherein the clearances on the outer peripheral side and the inner peripheral side are made larger compared with each other.   The scroll compressor according to claim 1, wherein the rigidity of the members constituting the fixed side sliding plate (28) is larger than that of the movable side sliding plate (27).   The scroll compressor according to claim 1, wherein unevenness is formed on the sliding surface on the fixed-side sliding plate (28) side.

Images