JPH0436085A - Scroll type compressor - Google Patents

Abstract

PURPOSE:To enhance the compression efficiency by applying the back pressure of high pressure gas to the rear surface of a mirror plate of a rotary scroll and the rear surface of a boss part on a stationary scroll body, and by applying the back pressure of middle pressure gas to a mirror plate of the stationary scroll. CONSTITUTION:High pressure gas discharged into a closed casing 1 is led to the rear surface of a mirror plate 31 of a rotary scroll 5 and to the rear surface of a boss part 40 of a stationary scroll body 36 so as to apply its back pressure thereto. Meanwhile, a compression chamber 67 is communicated with an interme diate pressure chamber 66 through a communication hole 45 so as to apply the back pressure to a mirror plate 39 of the stationary scroll body 36. With this arrangement, after elate of a slight time from the time of start, the gaps between the forward end parts of the laps 32, 45 of the scrolls 5, 6 and the mirror plates 31, 39 becomes gradually smaller, and they are finally meshed with each other in a substantially zero gap condition so that the volume of leakage of compression can be minimized. Thus, it is possible to obtain a high compression efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a scroll compressor used as a compressor constituting a refrigeration cycle of an air conditioner, for example.

(Prior art) For example, compared to a normal rotary compressor used as a compressor that constitutes the refrigeration cycle of an air conditioner,
Scroll compressors, which have extremely low motion noise and high compression efficiency, are increasingly being used.

This type of scroll compressor is constructed by housing a scroll compression mechanism section in which an orbiting scroll and a fixed scroll are meshed together and an electric motor section in a closed case. The orbiting scroll includes an end plate and a spiral wrap integrally provided on the end plate, and the fixed scroll includes:
It consists of an end plate and a spiral wrap integrally provided on the end plate. The electric motor unit drives the orbiting scroll, which makes an orbital motion and introduces a low-pressure refrigerant gas, which is a fluid to be compressed, into a compression chamber formed between each scroll, compresses it to a high pressure, and then discharges it. It is supposed to be done.

(Problems to be Solved by the Invention) The wrap of the orbiting scroll and the wrap of the fixed scroll mesh with each other to exert a compressive action, but it is extremely difficult to set the height dimensions of these wraps. That is, the tip end portions of each wrap face the inner surfaces of the end plates of the orbiting scrolls that face each other.

If the height dimension of the wraps is poorly controlled, these tips will come into strong sliding contact with the end plate, creating excessive resistance and making it impossible to perform smooth compression movements. Alternatively, if there is a gap greater than necessary between the tip of the wrap and the head plate, gas leaks from the gap to the low pressure side during compression, resulting in a non-negligible compression loss.

Further, a thrust force, which is an axial load, is applied to the orbiting scroll and the fixed scroll due to the effect of compressing the gas in the compression chamber. In particular, a fixed thrust receiver is brought into sliding contact with the rear side of the end plate of the orbiting scroll to prevent the orbiting scroll from floating more than necessary due to the thrust force.

However, in such a configuration, the end plate of the orbiting scroll and the thrust receiver come into extremely strong sliding contact, resulting in large resistance.

For example, in Japanese Patent Application Laid-Open No. 63-80088,
A low-pressure scroll compressor is shown that fills a closed case with refrigerant gas, compresses it, and discharges the high-pressure gas directly to the outside of the case. In this compressor, the end plate of the fixed scroll is attached and fixed to the closed case via a pair of leaf springs, and is movable by a small amount toward the orbiting scroll to minimize the gap between the wraps.

However, since this compressor is of a low pressure type, all the thrust force generated by compressing the fluid to be compressed is applied to the thrust receiver. In addition, by applying gas pressure to the back of the fixed scroll to overcome the spring force of the leaf spring and displace the fixed scroll by a small amount toward the orbiting scroll, the force obtained by subtracting the counterforce of the leaf spring from the gas force can also be applied to the orbiting scroll. is pushed in the axial direction, and the thrust force becomes even larger. Such a large thrust force means that the sliding loss with the thrust receiver becomes large, resulting in a decrease in mechanical efficiency and compression efficiency. In the above scroll compressor,
Because it is a low-pressure type, it has these drawbacks.

Further, in a general scroll compressor, the wrap of the fixed scroll receives a load in the thrust direction as well as a load in the radial direction as a result of the compression action. The above-mentioned fixed scroll is originally fixed so as not to be tilted, but this wrap is subjected to a load particularly in the radial direction, and a phenomenon occurs in which the scroll is tilted by a small amount with respect to the axis.

This amount of fall is influenced by the fitting of the sliding part, but in any case, it cannot be ignored because it leads to compression leakage, and some kind of fall prevention means must be adopted.

The present invention has been made in view of the above circumstances, and its purpose is to reduce the starting load by maintaining a gap between the orbiting scroll and the fixed scroll at the time of starting compression operation, and to reduce the starting load during operation. By reducing the gap to zero, it is possible to prevent leakage of incompressible fluid, ensure smooth movement of each scroll, and improve compression efficiency by reducing sliding loss. The object of the present invention is to provide a scroll compressor that prevents the scroll from collapsing and ensures smooth compression movement even when the scroll compressor receives a load in the radial direction.

[Structure of the Invention] (Means and Effects for Solving the Problems) That is, the present invention provides a scroll type in which an orbiting scroll connected to a main shaft and a fixed scroll are engaged with each other to form a compression chamber in a lower part of a closed case. A compression mechanism section and an electric motor section connected to the upper part of the scroll compression mechanism section via a main shaft are housed, and the high pressure gas compressed in the compression chamber of the scroll compression mechanism section is once discharged into a sealed case. In a high-pressure scroll compressor, the orbiting scroll is composed of an end plate that receives back pressure from high-pressure gas discharged into a closed case, and a spiral wrap integrally provided on this end plate, and a fixed scroll. The fixed scroll is composed of a main body and a cover, and the fixed scroll main body has an end plate having one end surface having a narrow gap with the lap of the orbiting scroll, and a tip portion of the end plate provided on one end surface of the end surface of the end plate of the orbiting scroll. A wrap that meshes with the wrap of the orbiting scroll with a narrow gap to form a compression chamber with the wrap, which is integrally protruded from the other end of the end plate and receives back pressure from the high pressure gas discharged into the sealed case. It consists of a boss part,
The cover is fixed within the sealed case, and supports the end face of the boss part and the peripheral end of the end plate of the fixed scroll main body so as to be freely displaceable in the thrust direction via leaf springs, and is connected to the end face of the end plate of the fixed scroll main body. This scroll type compressor is characterized in that an intermediate pressure chamber is formed as an airtight space that communicates with the compression chamber through a communication hole bored in the end plate between the scroll compressor and the compression chamber.

As a result, the high-pressure gas discharged into the sealed case is guided to the back side of the end plate of the orbiting scroll and the back side of the boss part of the fixed scroll body, giving back pressure, while the compression chamber and the intermediate pressure chamber are connected to the communication hole , which applies intermediate back pressure to the end plate of the fixed scroll. At startup, there is a gap between the end of the lap of the orbiting scroll and fixed scroll and the opposing end plate, so the startup load is extremely small. After startup, the above gap gradually becomes smaller over a short period of time, and eventually they mesh with each other in a state close to zero. This minimizes the amount of compression leakage from the gap between the tip of each wrap and the end plate, achieving high compression efficiency. It will be done. Further, even if the fixed scroll body receives a load in the radial direction, a leaf spring connecting the fixed scroll body and the cover is bent to prevent the fixed scroll body from falling down.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings, as a scroll compressor used, for example, in an air conditioner.

As shown in FIG. 1, numeral 1 in the figure is a hermetic case, and numeral 2 is a scroll compressor main body housed within the hermetic case 1. As shown in FIG. This scroll compressor main body 2 includes a scroll compression mechanism section 3 disposed at the bottom of a sealed case 1,
It is comprised of an electric motor part 4 connected to the upper part of this scroll type compression mechanism part 3.

The scroll type compression mechanism section 3 is composed of an orbiting scroll 5, a fixed scroll 6, and a support frame 7 that supports them.

The support frame 7 includes a bearing part 8 projecting from the center of the lower side thereof, and a boss part 9 having a larger diameter on the other side. The bearing portion 8 rotatably supports a main shaft portion 10a of a main shaft 10 that connects the scroll compression mechanism portion 3 and the electric motor portion 4. The boss portion 9 is formed with a crank chamber 11, which is a space whose lower end is open. Further, an oil supply hole A12a is provided at the base end of the boss portion 9 and communicates with the crank chamber 11. Furthermore, an oil supply hole B12b that opens into the crank chamber 11, and this oil supply hole B12b.
An oil supply hole Cl2c is provided which communicates with the main shaft portion 10a and opens opposite to the base end portion of the main shaft portion 10a.

A thrust receiver 13 is fitted into the crank chamber 11,
It is mounted and fixed via mounting screws 14...

Note that the circumferential surface of the crank chamber 11 and the fitting circumferential surface of the thrust receiver 13 are airtightly fitted with a seal ring 15 interposed therebetween.

Oil aC16c is provided in a part of the lower end surface of the thrust receiver 13, and the end of this oil groove C16c is connected to the thrust receiver 13.
Drain passage A1 provided from the lower end surface to the outer circumferential surface of
7a.

The drain passage A17a communicates with a drain passage B17b that opens on the outer peripheral surface of the boss portion 9 of the support frame 7. Therefore, the lower end surface of the thrust receiver 13 has an oil groove C16.
The portions other than c are in sliding contact with the orbiting scroll 6.

The support frame 7 constructed in this way is fixedly attached to the ring frame 18, which is fixed to the inner wall surface of the sealed case by means such as arc welding, through attachment screws 19. Parts of the ring frame 18 and the support frame 7 are cut out from each other, and even with the ring frame 18 and the support frame 7, the upper and lower parts of the sealed case 1 are integrally communicated.

The end of the main shaft 10a of the main shaft 10, which is rotatably supported by the bearing 8 of the support frame 7, has a thrust receiver 13 of the crank chamber 11, which has a larger diameter than the main shaft 10a.
A crank bin portion 10b inserted therein is integrally provided. An engagement hole 20 is provided from the lower end face of the crank bin part 10b to the vicinity of the upper end face thereof in a state eccentric to the axis of the crank bin part 10b. The portion 22 is rotatably fitted.

One end of the main shaft 10 opens into the engagement hole 20 of the crank bottle portion 10b, and a discharge passage A23a is provided across the middle of the main shaft portion 10g.

Since the discharge passage A23 is along the axis of the engagement hole 20, it is eccentric from the axis of the main shaft portion 10a. The upper end of the discharge passage A23a communicates with a discharge passage B23b provided along the axis of the main shaft portion 10a, and further communicates with a discharge passage C23c provided from the discharge passage B23b to the upper end, and these connecting portions check valve 24
is provided. The upper end opening of the discharge passage C23c is
It is closed by disk 25. A guide horizontal hole A26a is provided in the lower part of the disk 25, and a discharge passage C2
Connects with 3c. Note that the disk 25 is provided with an oil separation plate 2.
7 are integrally fitted.

An annular groove 28 for oil supply is provided on the circumferential surface of the connecting portion between the main shaft portion 10a and the crank bottle portion 10b, and the lower end portion thereof communicates with the annular groove 28, and extends upward toward the main shaft portion 10H. An oil groove A16g is provided in a spiral shape. Also,
A spiral oil groove B16b is formed on the inner peripheral surface of the metal ring 21.
A guide horizontal hole B26b is provided and is bored through the outer peripheral surface of the crank bin portion 10b via the metal ring 21.
communicate with. An oil supply hole D12d is provided penetrating from the upper end surface of the crank bottle portion 10b to the engagement hole 20. This oil supply hole D12d is connected to the metal ring 2.
It communicates with the guide horizontal hole B26b via the oil groove B16b of No. 1.

A balancer 30 integrally equipped with a pump 29 is fitted and fixed on the outer peripheral surface of the crank bin portion 10b of the main shaft 10.

The pump 29 and balancer 30 are rotatably housed in the crank chamber 11 inside the thrust receiver 13. The outer peripheral surface of the crank bin portion 10b is a thrust receiver 1.
There is a certain amount of gap with the inner circumferential surface of No. 3.

The orbiting scroll 5 includes a circular end plate 31, the boss portion 22 integrally protruding from one end face of the second end plate 31 on a compulsive circle, and a spiral wrap integrally protruding from the other end face. It consists of 32. A discharge port 33 is opened across the end plate 31 and the boss portion 22 and has a diameter that does not involve the wrap 32. This discharge boat 33 opens at the end face of the boss portion 22, and thus communicates with the discharge passage A23a provided in the main shaft 10.

Note that a key 34, which is an orgum ring mechanism, is fitted between the end surface of the end plate 31 on the side of the boss portion 22 and the support frame 7.

To further explain the orbiting scroll 5, the boss portion 22 is connected to the engagement hole 20 of the crank bin portion 10b.
The metal ring 21 is slidably engaged with the metal ring 21.

A seal ring 35 is interposed between the end face of the boss portion 22 and the end face of the engagement hole 20 to maintain airtightness. In addition,
The upper end surface of the end plate 31 of the orbiting scroll 5 is the crank bin part 1
It is assembled with a gap between the end face 0b and the thrust receiver 13, as described above, and slides into contact with the thrust receiver 13 except for the oil groove C16c.

The fixed scroll 6 includes a fixed scroll main body 36,
It is composed of the cover 37 described above. The cover 37 is
It is attached and fixed to the lower end surface of the support frame 7 via attachment screws 38.

As shown in FIGS. 2 and 3, the fixed scroll main body 36 includes a somewhat thick disk-shaped end plate 39, a boss portion 40 integrally provided on one end surface of this end plate 39, and Four intermediate pressure chamber portions 41 provided on the outer peripheral surface of the boss portion 40
, a spiral wrap 42 integrally protruding from the other end surface, and a pair of plate spring mounting protrusions 43, 43 provided oppositely to each other on the circumferential end and having a lower protrusion height than the above-mentioned wrap 42. be done.

A screw hole 4 is formed over a predetermined length from the end surface of the boss portion 40.
4 is provided. The mirror plate 39 has a pair of communication holes 45 located at positions that do not interact with the wrap 42.
．． 45 is bored and communicates with the intermediate pressure chamber recess 41. Further, a pair of positioning holes A46a, 46a are provided on the outer peripheral side of the wrap 42 of the mirror plate 39. A pair of screw holes 54a are provided on the end faces of the leaf spring mounting projections 43, 43, respectively.

As shown in FIGS. 4 and 5, the cover 37 has a first diameter that gradually decreases in diameter from one end surface side to the other end surface side. Second. Third fitting hole 48, 49.50
A large-diameter seal ring groove 51 is provided on the circumferential surface of the second fitting hole 49, and a small-diameter seal ring groove 52 is provided on the circumferential surface of the third fitting hole 50. On the end face of the first fitting hole 48, there is a stepped portion 53°5 for attaching a plate spring, which faces opposite to each other.
3 are formed, and a pair of screw holes 54b... are provided in each. Further, a pair of positioning holes B4 are provided at the deepest side end surface of the first fitting hole 48 and on the outside of the second fitting hole 49.
6b, 46b are provided, and a plurality of positioning holes C46c... are provided on the outer end surface of the first fitting hole 48.

Further, the end surface of the cover 37 on the side of the third fitting hole 50 is provided with a tapered recess 55 which is cut out so as to become gradually deeper in the axial direction from the middle of the end surface. A plurality of screw holes 56 are provided outside the tapered recess 55. A tapered hole 57 for attaching a suction pipe is formed in a part of the peripheral wall of the cover 37 so as to communicate with the first fitting hole 48 from the outer peripheral surface.
is provided.

As shown in FIGS. 1 and 6, the fixed scroll main body 36 is connected to the cover 37 by a pair of first leaf springs 58.
, 58 and a second leaf spring 59. That is, seal rings 60 and 61 are installed in each of the large diameter seal ring groove 51 and the small diameter seal ring groove 52 of the cover 37.
Interpose.

Then, the end plate 39 of the fixed scroll main body 36 is inserted into the first fitting hole 48 of the cover 37, the intermediate pressure chamber recess 41 is inserted into the second fitting hole 49, and the boss portion 40 is inserted into the third fitting hole 50. fit. In this state, the positioning holes A46a, 46a provided in the mirror plate 39 and the positioning hole B46b provided in the cover 37.

46b are opposed to each other, and a positioning pin 62 is inserted between them to accurately position each other. On top of that, a pair of leaf spring mounting protrusions 43.4 of the fixed scroll main body 36
3 and the plate spring mounting step portion 53.53 of the cover 37.
are connected via leaf springs 58 and 58. Attachment screws 63 are used to attach the first leaf spring 58. Further, the end surface of the boss portion 40 of the fixed scroll main body 36 and the end surface of the cover 37 on the side of the tapered recess 55 are connected via the second leaf spring 59. To install the second leaf spring 59,
Mounting screws 64 are used. After the fixed scroll main body 36 and cover 37 are assembled, the positioning bin 62 is pulled out.

As shown in FIGS. 6 and 7, the first leaf spring 58 has a substantially mountain-shaped bent bottom, and both protruding ends of the first leaf spring 58 are connected to the leaf spring mounting projections 4 of the fixed scroll main body 36.
In addition, the proximal end portion is attached to the plate spring attachment step portion 53 of the cover 37.

The second leaf spring 59, which connects the end surface of the boss portion 40 of the fixed scroll main body 36 and the end surface of the cover 37 on the side of the tapered recess 55, may have a disk shape, for example, as shown in FIG. Alternatively, as shown in FIG. 9, a space 65 is provided in which the parts other than the mounting part are cut out by punching,
It may also be a disc-shaped member 59A that is easily deformable.

In this way, due to the combination of the fixed scroll main body 36 and the cover 37, the intermediate chamber recess 41 provided around the boss portion 40 becomes a closed space sealed by the seal rings 60, 61, and the intermediate chamber A chamber 66 is formed. This intermediate pressure chamber 66 communicates with the wrap 32 through a communication hole 45° 45 provided in the end plate 39.

In this state, there is a slight gap between the peripheral end surface of the four intermediate chamber portions 41 and the end surface of the second fitting hole 49 of the cover 37. The fixed scroll main body 36 is attached to the cover 37 with the first
．． Since the fixed scroll main body 36 is connected via the second leaf springs 58 and 59, the fixed scroll main body 36 is supported with respect to the cover 37 so as to be freely displaceable in the thrust direction.

The fixed scroll 6 constructed in this manner is combined with the orbiting scroll 5. That is, the wrap 42 of the fixed scroll main body 36 and the wrap 3 of the orbiting scroll 5
2 is a compression chamber 67 that is engaged with each other and has a substantially crescent-shaped cross section and is surrounded by each other's wraps 42.32 and end plates 39.31.
is formed.

The tip of each wrap 42.32 is connected to the end plate 3 facing it.
1.39 It is assembled so that there is a narrow gap g between the end face and the end face.

The end plate 39 of the fixed scroll main body 36 is provided with communicating holes 45 and 45 passing through both end faces thereof, so that the intermediate pressure chamber 66 and the compression chamber 67 communicate with each other via the communicating holes 45.

An end portion of a suction pipe 68 provided through the sealed case 1 is fitted into the suction pipe attachment tapered hole 57 provided on the peripheral surface of the support frame 7 . This suction pipe 68 and the closed case 1 are sealed to maintain airtightness. On the other hand, a discharge pipe 69 is provided at the upper end of the sealed case 1,
It communicates with this inside.

An oil reservoir 70 for collecting lubricating oil is formed at the inner bottom of the sealed case 1. This oil level is normally slightly lower than the end surface of the bearing portion 8 of the support frame 7.

Therefore, almost all of the scroll type compression mechanism section 3 is immersed in the lubricating oil in the oil reservoir section 70.

The main shaft portion 10a of the main shaft 10 protruding from the bearing portion 8 of the support frame 7 has a rotor 7 constituting the electric motor portion 4.
1 is fitted. A thrust ring 72 and a wave washer 73 are interposed between the lower end surface of the rotor 71 and the end surface of the bearing portion 8 of the support frame 7, and receive the load of the main shaft 18 in the thrust direction.

A stator 74 constituting the electric motor section 4 is fitted onto the inner circumferential surface of the sealed case 1 . The inner circumferential surface of the stator 74 surrounds the outer circumferential surface of the rotor 71 with a narrow gap therebetween. Upper coil end 74 of the stator 74
A connection cord 75 extending from a is electrically connected to a terminal 76 provided at the upper end of the sealed case 1.

Next, the operation of the scroll compressor constructed in this way will be explained.

By energizing the electric motor section 4, the scroll compression mechanism section 3 introduces and compresses a fluid to be compressed, such as refrigerant gas. That is, the main shaft 10 is rotationally driven together with the rotor 71, and the orbiting scroll 5 engaged with the crank pin portion 10b makes an orbiting motion. The outer peripheral end side of the compression chamber 67 formed between the wrap 32 of the orbiting scroll 5 and the wrap 42 of the fixed scroll main body 36 becomes negative pressure,
Refrigerant gas is sucked through the suction pipe 68. The refrigerant gas is once introduced into the first fitting hole 48 of the cover 37 provided opposite to the suction pipe 68, and then further introduced into the compression chamber 67. The refrigerant gas is fed from the peripheral end of the compression chamber 67 toward the center and is compressed from the point where its volume becomes smaller. When the gas is fed into the compression chamber 67 at the center, the pressure increases to a predetermined high pressure. The highly pressurized gas is then discharged from the discharge port 33 provided in the orbiting scroll 5, and is discharged from the discharge passage A2 provided in the main shaft]0.
3a and the discharge passage B23b, it passes through the check valve 24. Furthermore, it is discharged into the sealed case 1 from the discharge passage C23c and the guide lateral hole A26a. In other words, this compressor is
This is a so-called high-pressure type in which the sealed case 1 is filled with high-pressure gas.

Furthermore, the high pressure gas is discharged through the discharge pipe 69 and guided to a predetermined location.

By the way, at the time of startup, the tips of the wraps 32° 42 of the orbiting scroll 5 and the fixed scroll main body 36 have a narrow gap g with the opposing end plates 39 and 31, so that the suction is sucked from there. Some of the refrigerant gas leaks. In other words, due to the gap g, the starting load can be extremely small, and smooth starting can be achieved.

Simultaneously with this compression movement, the pressure in the compression chamber 67 rises to a level near the pressure determined by the number of turns of each wrap 32, 42, etc. Therefore, the orbiting scroll 5 and the fixed scroll main body 36 are subjected to a thrust direction load in directions opposite to each other and a radial direction load in a radial direction relative to the wrap 32° 42 shape. As a result, the orbiting scroll 5 is attached to the thrust receiver 13 and the fixed scroll body 3
6 tries to be strongly pressed against the cover 37.

However, a part of the gas in the middle of compression in the compression chamber 67 passes through the communication hole 45. It is guided into the pressure chamber 66. Since the cover 37 is attached and fixed to the support frame 7, it is not affected by the gas pressure introduced into the intermediate pressure chamber 66.

The fixed scroll main body 36 is supported by the cover 37 via the first leaf spring 58 and the second leaf spring 59, so it is movable in the thrust direction, and the intermediate pressure chamber 66
It receives back pressure in the anti-thrust direction due to the gas pressure guided by the In other words, the fixed scroll main body 36 is pushed up by back pressure in the anti-thrust direction that overcomes the thrust force with a very small time difference after startup, and each wrap 3
The 2° 42 tip comes into contact with the opposing end faces of the mirror plates 39 and 31, thereby restricting gas leakage.

Along with the compression action, the pressure inside the sealed case 1 becomes high for a while, and this pressure is applied from the crank chamber 11 to the end plate 31 of the orbiting scroll 5 through the gap between the thrust receiver 13 and the crank pin portion 10b as back pressure.

At the same time, the cover 37 and the boss portion 40 of the fixed scroll main body 36 rotate toward the fixed scroll 6 through openings provided in a part of the ring frame 18 and the support frame 7.
This creates back pressure on the body.

The anti-thrust force, which is the back pressure applied to the orbiting scroll 5, is smaller than the thrust force due to the compression action. however,
By applying this anti-thrust force, the orbiting scroll 5 does not have to be strongly pressed against the thrust receiver 13. That is, a force in the opposite direction to the thrust force is applied, and the sliding loss between the end plate 31 of the orbiting scroll 5 and the thrust receiver 13 can be significantly reduced, and the orbiting scroll 5 can perform a smooth orbiting motion. This anti-thrust force can be arbitrarily set by changing the total area of the inner diameter area of the thrust receiver 13 and the area of the oil groove C16c.

On the other hand, in the fixed scroll 6, since the cover 37 is fixed to the support frame 7, the back pressure accompanying the high pressure inside the closed case 1 affects only the boss portion 40 of the fixed scroll body 36. As described above, back pressure is applied to the fixed scroll main body 36 also in the intermediate pressure chamber 66, and the resultant force is the back pressure applied to the boss portion 40. The difference between the resultant force of this anti-thrust force and the thrust force accompanying the compression action is actually the difference between the fixed scroll body 36
It is the force applied to Naturally, the resultant force of the anti-thrust force is larger, and the fixed scroll main body 36 is always pushed up and engaged with the orbiting scroll 5 during the continuation of the compression movement except at the time of startup, so that there is no compression leakage.

Here, to summarize the above-mentioned force relationships, (1) the force acting on the fixed scroll main body 36 is caused by the reaction in the intermediate pressure chamber 66 during startup or operation under the condition that the relationship of discharge side pressure > suction side pressure holds; Thrust force> The relationship of thrust force in the compression chamber 67 should be maintained.

■ The force relationship that acts on the fixed scroll main body 36 and the orbiting scroll 5 is as follows: The thrust force that acts on the fixed scroll main body 36 acts on the carboss portion 40, and the thrust force that acts on the anti-thrust car compression that acts on the anti-thrust car compression pressure chamber 66... - (A) To obtain the relationship between the thrust force acting on the orbiting scroll 5 due to Kerr compression>the anti-thrust force acting on the end plate 31.

Then, the force acting on the fixed scroll main body 36 and the orbiting scroll 5 is the above equation (A) + thrust force acting on the orbiting scroll 5 due to compression> anti-thrust force acting on the end plate 31, and eventually the boss of the fixed scroll main body 36 The anti-thrust force acting on the portion 40 and the anti-thrust force acting on the intermediate pressure chamber 66 are anti-thrust forces acting on the end plate 31 of the orbiting scroll 5.

Note that if the center of the intermediate pressure chamber 66 is configured to be slightly eccentric with respect to the center of the boss portion 40 of the fixed scroll main body 36, the back pressure applied to the end face of the boss portion 40 and the intermediate pressure applied to the intermediate pressure chamber 66 will cause The point of application of the resultant force of the applied forces coincides with the point of application of the force in the thrust direction generated by compressing the gas. Therefore, the fixed scroll body 36
As a result, the radial displacement of the wrap 42 is minimized and highly efficient operation is possible.

As described above, a load is applied to each wrap 32.degree. 42 in the radial direction as a result of the compression motion. In particular, since the fixed scroll main body 36 is supported by the cover 37 via the first leaf spring 58 and the second leaf spring 59, this wrap 42 receives a radial force and exerts a very small amount with respect to the axis. However, he tries to be defeated. However, the first leaf spring 58 and the second leaf spring 5
9 elastically bends to absorb the fall of the wrap 42 and prevent this precession.

Next, the supply state of lubricating oil in the scroll compression mechanism section 3 will be explained.

The lubricating oil in the oil reservoir 70 is guided from the oil supply hole A12a of the support frame 7 to the crank chamber 11 as the main shaft 1o rotates, and is blown to the outer periphery by the pump 29 rotating there. . And oil supply hole B12b
The oil is guided from the oil supply hole Cl2c to the oil SA 16a provided on the circumferential surface of the main shaft portion 10a of the main shaft 10. Therefore, smooth sliding between the main shaft portion 10a and the bearing portion 8 of the support frame 7 is ensured, and overflow occurs from the gap between the upper end portion of the main shaft portion 10a and the thrust ring 72.

Furthermore, a portion of the lubricating oil from the oil supply hole Cl2c communicates with the oil supply hole D12d provided in the crank bottle portion 10b and the oil groove B16b on the inner peripheral surface of the metal ring 21. Therefore, via the metal ring 21, the crank bin part 10b
The gas is accelerated by centrifugal force from the guide side hole B26b, and is discharged into the crank chamber 11. The oil is guided from the crank chamber 11 to the oil groove C16c of the thrust receiver 13 to ensure smooth sliding between the thrust receiver 13 and the end plate 3 of the orbiting scroll 5. Then, the oil is returned from the drain passage A 17a to the original oil reservoir 70 via a drain passage B 17b provided in the support frame 7.

[Effects of the Invention] As explained above, according to the present invention, a fixed scroll is composed of a fixed scroll main body and a cover, and the end plate and wrap of the fixed scroll main body are arranged in a narrow gap with respect to the wrap and end plate of the orbiting scroll. A back pressure is applied to the end plate of the orbiting scroll and the boss portion of the fixed scroll main body, and the gap between the cover and the end plate of the fixed scroll main body is used as an intermediate pressure chamber communicating with the compression chamber, and an intermediate back pressure is applied to the end plate. Since this is done, frictional resistance during startup is reduced and smooth startup is possible. Immediately after startup and during compression operation,
The gap between the wrap tip of each scroll and the end plate is close to zero, and the amount of compression leakage from these gaps is minimized, making it possible to obtain high compression efficiency. In addition, since the fixed scroll main body and the cover are connected via a leaf spring, even if the wrap of the fixed scroll main body receives a load in the radial direction during operation, the above leaf spring prevents the wrap from collapsing and maintains a stable This has the effect of performing compression operation.

[Brief explanation of drawings]

1 to 8 show an embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view of a scroll compressor, FIG. 2 is a plan view of a fixed scroll main body, and FIG. 3 is a 4 is a plan view of the cover, 5 is a longitudinal sectional view of the cover, 6 is a plan view of the fixed scroll installed in the cover, and 7 is a longitudinal sectional view taken along line - ■. Plan view of leaf spring No. 1, No. 8
The figure is a plan view of the second leaf spring, and FIG. 9 is a plan view of the second leaf spring showing another embodiment of the present invention. 1... Sealed case, 5... Orbiting scroll, 67.
... Compression chamber, 6... Fixed scroll, 3... Scroll type % type % end plate (of the orbiting scroll), 32... Wrap (of the orbiting scroll), 39... End plate (of the fixed scroll body) , 42... Wrap (of fixed scroll body), 40
...Boss part (of the fixed scroll body), 36...Fixed scroll body, 58...First leaf spring, 5 pieces...
・Second leaf spring, 37...Cover 45...Communication hole, 66...Intermediate pressure chamber. Applicant's Representative Patent Attorney Takehiko Suzue

Claims (1)

[Claims] A scroll-type compression mechanism section consisting of a closed case, an orbiting scroll housed in the lower part of the closed case and connected to the main shaft, and a fixed scroll that meshes with the orbiting scroll to form a compression chamber, and this scroll-type compression mechanism. In a high-pressure scroll type compressor, the high-pressure scroll type compressor is equipped with an electric motor part connected to the upper part of the part via the main shaft, and discharges high-pressure gas compressed in the compression chamber of the scroll type compression mechanism part into a sealed case. , the above-mentioned orbiting scroll is composed of an end plate that receives back pressure from high-pressure gas discharged into a sealed case, and a spiral wrap that is integrally provided on this end plate, and the above-mentioned fixed scroll has one end surface that is connected to the above-mentioned An end plate with a narrow gap between the wrap of the orbiting scroll,
A wrap that is integrally provided on one end surface of the end plate, the tip of which has a narrow gap with the end plate of the orbiting scroll, and meshes with the wrap of the orbiting scroll to mutually form a compression chamber;
A fixed scroll main body consisting of a boss part integrally protruding from the other end of the end plate and receiving back pressure from high pressure gas discharged into the sealed case, and an end face of the boss part of the fixed scroll main body fixed to the sealed container. and a cover that supports the peripheral end of the end plate movably in the thrust direction through leaf springs, and the compression chamber and the end plate of the fixed scroll body are bored between the end plate of the fixed scroll body and the cover. 1. A scroll compressor characterized by being provided with an intermediate pressure chamber which is an airtight space communicating through a communication hole.