JPH0134313B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scroll compressor having a structure in which an orbiting scroll is pressed against a fixed scroll so that the pressure in a back pressure chamber is an intermediate pressure in a working pressure range.

[Prior art]

An example of a conventional scroll fluid machine is a scroll compressor, and will be explained with reference to FIG.

An orbiting scroll 1 and a fixed scroll 2 are combined facing each other, and the fixed scroll 2 and frame 3 are fixed so that the orbiting scroll 1 is sandwiched between the fixed scroll 2 and a frame 3, and the orbiting scroll 1 is held so as to be able to rotate. .

The suction refrigerant gas is sucked in through the suction pipe 4 and flows from the outer peripheries of the fixed scroll 2 and the orbiting scroll 1 into the suction chamber 28 formed by the two scrolls. The orbiting scroll 1 is prevented from rotating by an Oldham key 5 and an Oldham ring 6, and performs a rotational movement, and a crankshaft 7 having an eccentric shaft portion rotates (shifts) through a rotation bearing 8, sequentially moving around a closed space 9. The refrigerant gas is transferred toward the center, compressed, and discharged into the discharge chamber 11 from the discharge port 10 provided at the center of the fixed scroll 2 .

Further, the crankshaft 7 is supported by an upper main bearing 12 and a lower main bearing 13 provided on the frame 3, and is rotated by the driving force of motors 14 and 15. On the other hand, the orbiting scroll 1 is provided with a communication hole 17 that communicates the closed space 9 with the back pressure chamber 16, and the pressure inside the back pressure chamber 16 is an intermediate pressure between the suction pressure and the discharge pressure.

Further, oil holes 18 and 19 are provided in the crankshaft 7, and the oil hole 18 supplies oil to the lower main bearing 13, and the oil hole 19 supplies oil to the upper main bearing 19, the thrust bearing, and the swing bearing 8. Further, grooves 20, 21, 22 are provided in the axial direction on the shaft surface of each bearing portion of the crankshaft 7, and the lower end of the crankshaft 7 is in an oil sump 23.
The back pressure chamber 16 and the oil reservoir 23 are electrically connected through the oil hole 19 and the grooves 20 and 21. Since the oil sump 23 is at the discharge pressure, oil is supplied to the swing bearing 8 and the upper main bearing 12 due to the pressure difference with the back pressure chamber 16, and then accumulates in the back pressure chamber 16 and flows through the through hole 17. and is guided to the closed space 9. On the other hand, the space 2 at the upper end of the crankshaft 7
4 is supplied with oil through an oil hole 19, and an oil hole 25 provided in the orbiting scroll 1
Oil is supplied to the end plate 26 of the fixed scroll 2.

Since the orbiting scroll 1 is pressed against the fixed scroll 2 by the intermediate pressure, an oil groove 27 is provided in the end plate 26 of the fixed scroll 2.
It is intermittently connected to the oil hole 25 and supplies oil to the contact surface 26 of both end plates. Therefore, the pressure inside the oil groove 27 is almost equal to the discharge pressure, so if the contact surfaces 26 of both end plates are not in close contact, the oil groove 27 will flow into the suction chamber 28.
This had the disadvantage that the volumetric efficiency decreased because the oil inside flowed. In addition, the contact area of the contact surfaces 26 of both end plates is large, as it is the entire surface of the outer end plate of the spiral wrap of the orbiting scroll 1 and the entire end surface of the fixed scroll 2 facing this, which has the disadvantage that the contact resistance is large and the driving force becomes large. . In addition, in order to provide the oil groove 27 in the end plate of the fixed scroll 2, it is necessary to increase the outer diameter of the orbiting scroll 1, and as the outer diameter increases, the diameter of the orbiting scroll 1 sandwiched between the fixed scroll 2 and the frame 3 must be increased. This has the drawback that the circumferential speed of the periphery increases, which agitates the oil accumulated in the space within the outer periphery of the orbiting scroll 1, increasing the driving force.

In addition, in the case where oil is supplied to the contact surface of both mirror plates through the oil hole 19 in the crankshaft 7 and the oil hole 25 in the orbiting scroll 1, when the orbiting scroll 1 is stopped, etc., the orbiting scroll 1 separates from the fixed scroll 2, and both mirror plates come into contact If a gap occurs in the surface 26, the oil in the oil sump 23 will flow through the oil hole 19,
The oil moves to the suction chamber 28 through the space 24, the oil hole 25, the oil groove 27, and the gap, and there is no oil in the oil sump 23, which has the disadvantage of causing a bearing burnout accident.

Regarding these matters, JP-A No. 55-160192, 57
- There are issues such as No. 46001.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into consideration the fact that oil flows into the suction chamber when the adhesion of the end plate decreases, and there is a problem in that the volumetric efficiency decreases due to the flow of oil.

Furthermore, insufficient consideration has been given to the increase in contact resistance due to the large sliding contact area of the end plate, resulting in the problem of increased driving force.
Furthermore, no consideration was given to stirring the oil accumulated on the outer periphery of the orbiting scroll.
This also caused the problem that the driving force increased. Furthermore, as shown in Figure 1, in the case of a type that supplies oil to the sliding surface of the head plate through the oil hole in the crankshaft, the orbiting scroll separates from the fixed scroll when the operation is stopped, creating a gap on the contact surface of the head plate. No consideration was given to the fact that if this occurs, the oil in the oil sump will move to the suction side (low pressure) through the gap due to the pressure difference, and the oil in the oil sump will be insufficient when restarting. However, there was a problem with insufficient bearing oil supply, which caused bearing burnout accidents.

An object of the present invention is to provide a scroll compressor that reduces oil agitation loss due to the orbiting scroll, ensures oil supply to the seat surface of the end plate, and provides a good sealing effect.

[Means to solve the problem]

The above object has a fixed scroll and an orbiting scroll that form a spiral wrap on an end plate, and an actuating section that makes an orbiting motion of the orbiting scroll while sliding the outer peripheral surfaces of the end plates of both scrolls in contact with each other; A frame is integrally fixed to the back of the head plate on the side opposite to the lap, and a back pressure chamber is created where intermediate pressure between high and low pressure is applied, and the oil supplied to the bearings etc. is finally discharged into the back pressure chamber. A bearing part oil supply passage to be disposed of, a conduction hole for guiding oil discharged into the back pressure chamber to the sealed space of the operating part, and a drive shaft for causing the orbiting scroll to orbit are provided penetrating through the frame; The contact sliding surface of the end plate of the fixed scroll is formed in the shape of a ring along the edge of the fixed scroll near the closed space and has a width equal to or less than the orbiting radius of the orbiting scroll, and the outside of the ring-shaped contact surface is formed in a recessed part. At the same time, the recess and the frame form an annular space filled with oil that communicates with the back pressure chamber, and the outer circumferential portion of the end plate of the orbiting scroll during the orbiting movement moves in and out of the space to collect oil. This is achieved by creating a structure that allows it to be wetted with water.

[Effect]

A seat surface 31, which is a contact surface between the fixed scroll 29 and the end plate of the orbiting scroll 30, is formed in a ring shape with the same width all around. Therefore, uniform surface pressure is always maintained and a stable sealing effect is obtained. In addition, the seat surface 31 is a ring-shaped sliding surface.
The width 34 is made smaller than the orbiting diameter so that when the contact surface moves, the original contact surface is completely exposed to the oil atmosphere and the upper surface of the end plate 35 of the orbiting scroll is sufficiently wetted with oil. Therefore, the next time the contact surface returns to its original position due to the orbiting motion of the orbiting scroll, sufficient oil can be supplied. Since the groove 33 provided in the fixed scroll 29 is formed as an annular groove around the entire circumference, the orbiting scroll 30
While rotating, the outer peripheral portion of the end plate 35 moves in and out of the annular space 37 formed by the groove 33 and the frame 3.

On the other hand, the oil supplied to the upper main bearing 12 and the thrust bearing 40 through the oil hole 19 and the oil supplied to the swing bearing 8 flow into the back pressure chamber 16, which eventually becomes full and further flows into the annular space 37. The upper surface of the end plate 35 of the orbiting scroll 30 is wetted with oil.

Therefore, even if the contact surface of the end plate of the orbiting scroll separates from the contact surface of the end plate of the fixed scroll when the operation is stopped, the oil in the annular space 37 and the oil in the back pressure chamber 16 may escape to the suction side. Since the oil does not escape, there is no risk of insufficient oil supply and bearing burnout accidents when restarting.

Hereinafter, one embodiment of the present invention will be described in Fig. 2, Fig. 2a,
This will be explained based on FIGS. 3 and 3a.

Portions with the same reference numerals in FIGS. 2 and 3 indicate the same or equivalent portions as in the prior art, and explanations of their configurations and operations will be omitted. 2 and 2a show an example of a structure according to the invention.

Figures 3 and 3a show a fixed scroll according to the invention.

The fixed scroll 29 and the orbiting scroll 30 are in close contact with each other at a seat surface 31, which is a ring-shaped sliding surface formed on the edge of the fixed scroll, and refrigerant gas or It has a structure that prevents oil from flowing. Further, on the outside of the seat surface 31, a concave groove 33 provided in the fixed scroll 29 is formed as an annular groove around the entire circumference. An annular space 37 is formed by the annular groove and the frame 3, and the annular space 37
communicates with the back pressure chamber 16.

In addition, the width 34 of the seat surface 31 is made smaller than the orbiting radius, and the relationship between the outer diameter (D) of the orbiting scroll and the diameter (d) including the outermost compression chamber of the fixed scroll is expressed by assuming the orbiting radius as r. When, D<4r+d. Moreover, 36 is a shallow groove, and the sliding surface of the fixed scroll is cut into an arc shape, and the seat surface is formed into a ring shape by this processing. Further, the size of the mirror plate 35 of the orbiting scroll 30 is set to a size that maintains the diameter of the seat surface 31 of the fixed scroll 29 when the orbiting scroll 30 performs a rotational movement. The outer side of the seat surface 31 on the upper surface of the end plate 35 of the orbiting scroll 30 is wetted with oil because the back pressure chamber 16 is filled with oil as described in the prior art.

Therefore, the end plate 35 of the orbiting scroll 30 wetted with oil slides on the seat surface 31, so that the oil supply characteristics are good.

That is, when the crankshaft 7 is driven by the motors 14 and 15 to cause the orbiting scroll 30 to orbit, the orbiting scroll 30 moves in the direction shown by the arrow in FIG. Make sure that the top surface of the mirror plate is sufficiently wetted by the oil that accumulates. Then, when the orbiting scroll 30 moves in the direction of the arrow as shown in FIG. It maintains contact with the ring-shaped sheet surface 31 of No. 29 while exhibiting sufficient sealing properties.

The outer circumferential portion of the end plate 35 is constantly moved in and out of the annular space 37 formed around the entire circumference as it rotates moment by moment, so that the upper surface of the end plate is sufficiently wetted with oil.

Furthermore, as mentioned above, the width of the seat surface 31 is made smaller than the turning radius, so as shown in FIG. 2a, the contact surfaces overlap between the contact position before the seat surface 31 is moved and the contact position after the movement. This makes the oil supply to the seat surface 31 more reliable.

During these swirling movements, the suction refrigerant gas is compressed and becomes a high-pressure gas, which is discharged from the discharge port 10 into the discharge chamber 11 .

Further, the pressure difference between the inner and outer sides of the outermost chamber 32 and the annular space 37 with the seat surface 31 as a border is the pressure difference between the intermediate pressure and the low pressure.
The amount leaking to 2 is small.

Further, the size of the end plate 35 of the orbiting scroll 30 can be made small because it is sufficient to maintain the seat surface 31 as described above.

Further, since there is no need to provide a special oil supply hole in the orbiting scroll 30, the structure becomes simpler.

Furthermore, even if the outer periphery of the end plate 35 of the orbiting scroll 30 enters the annular space 37, since the concave groove 33 is provided around the entire circumference, the space volume becomes large and there is little stirring loss even when the oil is stirred.

Also, it is desirable that the seat width be as narrow as possible than the turning radius without losing the sealing effect, but conversely, even if the width is larger than the turning radius, if it is ring-shaped, the pressure distribution will be well-balanced. Of course, it may be made larger as long as it is within the range where refueling is possible.

〔Effect of the invention〕

Since the present invention is configured as described above, drive loss due to oil agitation is reduced, and oil can be reliably supplied to the head plate sheet surface.

[Brief explanation of drawings]

FIG. 1 shows a structural diagram of a conventional scroll compressor. FIG. 2 shows a structural diagram of a scroll compressor showing an embodiment of the present invention. FIG. 2a shows a state diagram of the orbiting scroll after the orbiting movement, FIG. 3 shows a sectional view of a fixed scroll of a scroll compressor according to an embodiment of the present invention, and FIG. 3a shows a plan view of FIG. 3. 1... Orbiting scroll, 2... Fixed scroll, 3... Frame, 16... Back pressure chamber, 32...
outermost chamber, 31... seat surface, 33... concave groove,
35... Mirror plate of rotating scroll, 37... Annular space.

Claims (1)

[Claims] 1. A fixed scroll and an orbiting scroll having a spiral wrap formed on the end plate, an operating section that makes the orbiting scroll orbit while sliding the outer circumferential surfaces of the end plates of both scrolls, and A back pressure chamber is formed by the fixed scroll and a frame integrally fixed on the back of the lap side, and is subjected to an intermediate pressure between high and low pressure.The oil supplied to the bearings, etc., is finally discharged into the back pressure chamber. A bearing oil supply passage, a conduction hole that guides the oil discharged into the back pressure chamber to the sealed space of the operating section, and a drive shaft for rotating the orbiting scroll are provided through the frame, and the fixed The contact sliding surface of the end plate of the scroll is formed in the shape of a ring along the edge of the fixed scroll near the closed space and has a width equal to or less than the orbiting radius of the orbiting scroll, and the outside of the ring-shaped contact surface is formed into a recess. At the same time, the recess and the frame form an annular space filled with oil that communicates with the back pressure chamber, and the outer periphery of the end plate of the orbiting scroll during the orbiting movement moves in and out of the annular space to fill the oil. A scroll compressor characterized in that it is wetted with water.