JPH0436086A - Scroll type compressor - Google Patents

Abstract

PURPOSE:To prevent a stationary scroll body from turning over, by providing the stationary scroll body with an annular protrusion which projects along the peripheral end part of a mirror plate up to a height equal to that of a lap, separately from the lap, and which has a fluid communication cut-out in a part thereof. CONSTITUTION:A stationary scroll body 45 is provided with an annular protrusion 50 which is projected along the peripheral end part of a mirror plate 46, separately from a lap 49, up to a height equal to that of the latter, and which has a fluid communication cut-out. With this arrangement, even though a radial load is applied to the lap 49 so that the lap 49 falls, the forward end of the annular protrusion 50 abuts against a rotary scroll 5 over the entire periphery thereof, and accordingly, it is possible to prevent the stationary scroll from falling.

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 lifting 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,
This is a low-pressure scroll compressor that fills a closed case with refrigerant gas and compresses the gas to a high pressure, which is then discharged 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 and overcoming the spring force of the leaf spring to slightly displace the fixed scroll toward the orbiting scroll, the force obtained by subtracting the reaction force of the spring force 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.

Furthermore, in a general scroll compressor, both the orbiting scroll and the fixed scroll are set to be concentric with the center of the end plate and the center of the base circle that determines the shape of the wrap.

With such a configuration, the thrust direction load applied to these scrolls will be applied at a position shifted from the center by 1/2 of the base circle radius. Therefore, when back pressure is applied to a scroll to cause displacement of the opposing scroll, the point of action of the back pressure does not coincide with the point of action of the load in the thrust direction, resulting in a problem that the compression motion lacks stability.

Furthermore, in this type of 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 a phenomenon occurs in which the wrap is subjected to a load, especially in the radial direction, and 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.

On the other hand, in scroll compressors that have a high pressure inside a sealed case, there are those in which the scroll compression mechanism is located at the bottom and the electric motor at the top, and those in which the compression mechanism and the electric motor are upside down. In particular, placing the scroll compression mechanism at the bottom and the electric motor at the top is more stable and is therefore often used. In this case, the compression mechanism section is immersed in a lubricating oil reservoir formed at the inner bottom of the sealed case, and communicates with the compression chamber via an oil supply passage. As the compression mechanism performs the compression operation, the lubricating oil in the oil reservoir is supplied to the compression chamber through the oil supply passage.

However, when the pressure inside the sealed case is lower than the intermediate pressure of the compression chamber, such as during startup, gas that is being compressed in the compression chamber leaks back into the sealed case via the oil supply passage. After a certain amount of time has passed after startup, the pressure inside the sealed case becomes higher than the intermediate pressure in the compression chamber, so there is no backflow leakage of gas, but the compression loss due to the amount that has already leaked cannot be ignored.

For example, in Japanese Patent Application Laid-open No. 1-177483, a back pressure chamber is formed in the anti-compression space of an orbiting scroll, and an oil sump in a discharge chamber leading to a discharge port or an oil sump leading to the discharge chamber and a throttle passage are connected to the back pressure chamber. A high-pressure scroll compressor is disclosed which communicates with a compression space via an oil injection passage and includes a check valve device in the middle of the oil injection passage.

However, with such a configuration, an oil reservoir is formed in the upper part of the compression chamber, and the back surface of the fixed scroll is a discharge gas space, resulting in a complicated oil supply passage. Furthermore, it is extremely difficult to control the optimal amount of oil supply under all operating conditions, resulting in low reliability and disadvantages in terms of cost.

The present invention has been made by paying attention to the above-mentioned circumstances.
The purpose of this is that at the start of compression operation,
To provide a scroll type 6-compressor compressor that maintains the gap between the orbiting scroll and the fixed scroll to reduce the startup load, and reduces the gap to zero during operation to prevent leakage of incompressible fluid and improve compression efficiency. This is what I am trying to do.

A second object of the present invention is to provide a scroll compressor that prevents the wrap of the fixed scroll from collapsing and ensures smooth compression movement even when the wrap receives a load in the radial direction. It is something.

A third object of the present invention is to provide a scroll compressor that reliably prevents leakage of compressed fluid from an oil supply passage during startup.

[Configuration of the Invention (Means and Effects for Solving the Problems) That is, the present invention comprises a scroll-type compression mechanism section in which an orbiting scroll and a fixed scroll are engaged with each other to form a compression chamber in a lower part of a closed case; In a high-pressure scroll type compressor that houses an electric motor part connected to the upper part of the scroll type compression mechanism part and once 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 constituted by an end plate that receives back pressure from high-pressure gas discharged into a sealed case, and a spiral wrap integrally provided on this end plate, and the above-mentioned fixed scroll is constituted by a fixed scroll body and a cover. The fixed scroll main body includes an end plate having one end surface having a narrow gap with the wrap of the orbiting scroll, and an end plate provided on one end surface of the end surface and having a tip thereof having a narrow gap with the end surface of the orbiting scroll. The cover consists of a wrap that meshes with the wrap of the orbiting scroll and mutually forms a compression chamber, and a boss that 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. , supports the fixed scroll main body so as to be freely displaceable in the thrust direction, and forms an intermediate pressure chamber, which is an airtight space, between the fixed scroll main body and the end plate, and transmits the intermediate pressure through a communication hole bored in the end plate. The scroll compressor is characterized in that a chamber communicates with 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 gap gradually becomes smaller over a short period of time, and eventually they mesh in a state close to zero. Therefore, the amount of compression leakage from the gap between the end portions of the wraps and the end plate can be minimized, and high compression efficiency can be obtained.

Further, the present invention provides the fixed scroll main body with an annular protrusion that is separate from the wrap along the peripheral edge of the end plate, projects at the same height as the wrap, and has a notch for fluid conduction in a part. 1. A scroll compressor according to claim 1, characterized in that:

As a result, even if the wrap of the fixed scroll main body falls down due to a load in the radial direction, the tip of the annular projection contacts the orbiting scroll over the entire circumference, thereby preventing the wrap from falling down.

Further, the present invention forms an oil reservoir for collecting lubricating oil in the inner bottom of the sealed case, communicates the oil reservoir with the compression chamber through an oil supply passage, and provides a compression chamber in the middle of the oil supply passage. The scroll compressor according to claim 1, further comprising a backflow prevention means for preventing backflow of the fluid to be compressed from the compressor to the oil reservoir.

This prevents leakage of the compressed fluid in the compression chamber during compression, particularly when the internal pressure of the sealed case is low, such as during startup.

(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,
The scroll compressor #1 is composed of an electric motor section 4 connected to the upper part of the compressor section 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.

As shown in FIGS. 3 to 5, the support frame 7 includes a bearing portion 8 projecting from the center of the lower side thereof, and a boss portion 9 having a larger diameter on the other side. The bearing part 8
An engagement hole 1o opens at a concentric position with the engagement hole 10, and a pump relief hole 11 with a larger diameter than this, and a pump relief hole 11 with a larger diameter than this, and a pump escape hole 1o that is concentric with the engagement hole 10 and extends over the raised T pivot portion 9. The thrust receiver having a large diameter has an engagement hole ] 2 and a scroll escape hole 13 having a large diameter. In addition, in the thrust receiver, a seal ring 71#14 is provided on a part of the circumferential surface of the engagement hole 12. At the base end of the bearing section 8,
The oil supply hole Al 5a that communicates with the pump escape hole 11 and the outer periphery of the boss portion 9, the oil supply hole B 1.5b that communicates between the circumferential surface of the bearing portion 8 and the engagement hole 10, and the oil supply hole 15b in the middle Oil supply hole C that communicates with the above pump escape hole 1F
15c is provided. The open end of the oil supply hole B15b is closed by a blind plug a. Note that 16.16 is the key hole of the Oldham mechanism, and 17... is the punch hole.

As shown again in FIG. 1, a main shaft portion 19 of a main shaft 8 constituting the electric motor portion 4 is rotatably supported by the bearing portion 8 of the support frame 7. As shown in FIG. The above thrust receiver has the engagement hole 2,
The thrust receiver 2o is fitted and fixed via the mounting screw 21. A seal ring 22 is inserted into the seal ring 'a14, and the engagement hole 12 of the thrust receiver and the thrust receiver 20 are kept airtight. A cover 23 , which will be described later and which constitutes the fixed scroll 6 , is attached and fixed to the lower end surface of the support frame 7 via attachment screws 24 . The support frame 7 constructed in this manner is fixedly attached to a ring frame 25, which is fixed to one inner wall surface of the sealed case by means such as arc welding, via attachment screws 26. The ring frame 25 and support frame 7
A communication portion 27 that communicates with each other is provided in a part of the ring frame 25, so that the upper and lower parts of the sealed case 1 bordered by the ring frame 25 and the support frame 7 are in communication with each other.

On the other hand, the main shaft 18 is as shown in FIGS. 6 to 9. That is, this includes a rotor shaft portion 28 whose peripheral surface is partially cut flat at one end, and the main shaft portion 19 which is an intermediate portion and is pivotally supported by the bearing portion 8 of the support frame 7.
and a crank pin part 2 which is the other end and has a larger diameter than the main shaft part 19 and has a mutually connected part protruding like a flange.
It consists of 9.

A discharge passage A30a is provided along the axis extending from the end surface of the rotor shaft portion 28 to a midway portion of the main shaft portion 19. An engagement hole 31 is opened in the crank pin portion 29 at a position offset by a predetermined amount from the axis, and a discharge passage B50b is provided which communicates with the engagement hole 31 and the discharge passage A30a. Since the discharge passage B50b is provided along the axis of the engagement hole 31, its axis is eccentric to the axis of the discharge passage A30a.

An oil groove A32a is provided obliquely on the outer circumferential surface of the main shaft portion 19 from the portion where the crank pin portion 29 is connected to the main shaft portion 19. Further, a ring ring 33 is provided over the circumferential surface of the engagement hole 31, and an oil groove B52b is provided from the end surface of the crank pin portion 29 to intersect with the ring ring 33 and extend across the end surface of the engagement hole 31. The intersection position of this ring 33 and the crank pin part 29
An oil guide horizontal hole 34 passes through the outer peripheral surface, and an oil supply hole Di 5d passes through the end face of the engagement hole 31 and the outer peripheral surface of the crank pin portion 29. This oil supply hole DI 5
d communicates with the oil groove A32a.

As shown again in FIG. 1, a balancer 36 integrally provided with a pump 35 is fitted and fixed on the outer peripheral surface of the crank pin portion 28 of the main shaft 18. The pump 35 and balancer 36 are rotatably housed in a crank chamber 37 formed in a concave portion of the thrust receiver 20. A certain amount of clearance exists between the inner peripheral surface of the thrust receiver 20 and the outer peripheral surface of the crank pin portion 29. Further, only a portion of the lower end surface of the thrust receiver 20 has a gap, and the other portion faces the orbiting scroll 6 so as to be in sliding contact. The above thrust receiver 20
The part that has a gap with the orbiting scroll 6 at the lower end is an oil groove C.
32c, and one end thereof communicates with a drain passage A38a provided from the lower end surface to the outer peripheral surface. The drain passage A38a communicates with a drain passage B58b that opens on the outer peripheral surface of the boss portion 9 of the support frame 7.

As shown in FIGS. 10 to 12, the orbiting scroll 5 includes a circular end plate 39, a boss portion 40 integrally protruding from one end surface of the end surface of the end plate 39, and a boss portion 40 integrally provided on the other end surface. It consists of a spiral wrap 41 that is integrally provided.

A discharge port 42 with a diameter that does not engage the wrap 41 is located at a position offset by a predetermined amount from the center of the mirror plate 39.
is open. This discharge port 42 is connected to the boss portion 40.
are arranged in series along the axis of the tube, and are opened at this end surface. In addition,
On the end surface of the mirror plate 39 on the side of the boss portion 40, a key/g43, 43 of the organ ring mechanism is provided along one direction along the peripheral edge thereof.

As shown again in FIG. 1, the boss portion 4 of the orbiting scroll 5
0 is slidably engaged with the engagement hole 31 of the crank pin portion 29. The end face of this boss portion 40 and the engagement hole 3
A sill ring 44 is interposed between the end face of 1 and the end face of 1. Note that the upper end surface of the end plate 39 of the turning scroll 5 is connected to the crank pin portion 2.
9 is assembled with a gap between the end face and the thrust receiver 2.
0 means oil f, which makes sliding contact except for the C32c part. The keyway 43.43 and the keyway 16.16 provided in the support frame 7 are assembled with their positions shifted by 90 degrees, and a key K, which is an orgum ring mechanism, is slidably fitted into these.

The fixed scroll 6 includes a fixed scroll main body 45,
It is composed of the cover 23 described above.

The fixed scroll main body 45 is shown in FIGS. 13 to 15.
As shown in the figure, a somewhat thick disk-shaped end plate 46,
A boss portion 47 integrally provided on one end surface of the mirror plate 46 on the same aperture circle, a hooking step portion 48 having a larger diameter than this, a spiral wrap 49 and an annular protrusion 50 integrally provided on the other end surface. It consists of

An oil supply hole E15e is opened extending a predetermined length from the end surface of the boss portion 47 and has a snap ring groove 51 in a portion of its circumferential surface. An oil supply hole F15f communicating with this oil supply hole E15e and having a diameter smaller than this diameter is provided up to the middle part of the end plate 46. Then, from the peripheral end surface of the end plate 46, the oil supply hole F1 is
A refueling hole 015g is provided to intersect orthogonally with 5f and extend over a predetermined length to the vicinity of the peripheral end surface. Above wrap 49
The end surface of the end plate 46 and the oil supply hole 01 that have no relation to
A pair of oil supply holes H15h, 15h are provided over the 5g midway portion. A seal ring groove 52 is provided on the circumferential surface of the engaging step portion 48, and a plurality of screw holes 53 are provided on the end surface.
a... and a plurality of positioning holes 53b... are provided. Further, a pair of communication holes 54 and 54 are bored across the end face of the engaging step portion 48 and the end face of the end plate 46. These communication holes 54, 54 must be located at positions on the end surface of the end plate 46 where they do not come into contact with the wrap 49.

The annular protrusion 50 is provided along the peripheral edge of the mirror plate 46 so as to surround the wrap 49 located inside the annular protrusion 50 . This protruding height is
A pair of notches 55, 55 are provided at opposing positions that correspond to the protruding height of the wrap 49.

As shown in FIGS. 16 to 18, the cover 23 consists of a disc-shaped base 56 and a bearing boss 57 integrally projecting from one end surface of the base 56. A plurality of tapped holes 58 are provided at the peripheral end of the base portion 56, and a plurality of positioning holes 59a pass through the base portion 56, and a pair of blind positioning holes 59b are provided on the inside thereof. , 59b are provided.

A fitting hole 61 having a seal ring groove 60 is opened in a part of the circumferential surface of the bearing boss portion 57, and this fitting hole 61 is connected to a receiving hole 61 provided in the base portion 56 having a larger diameter. communicates with the hole 62. Furthermore, the receiver is placed around the hole 62,
For example, fan-shaped empty grooves 63 are provided at four locations.

As shown again in FIG. 1, the cover 23 is accurately positioned on the support frame 7 by the positioning pins 64, and is then fixed to the support frame 7 via the mounting screws 24. The boss portion 47 of the fixed scroll main body 45 is located in the fitting hole 61 of this cover 23, and the engaging stepped portion 48 is located in the receiving hole 62, and the seal rings 65a, 65 are located in the receiving hole 62, respectively.
They are airtightly fitted via b. One end of the leaf spring 66 is fixed to the cover 23 via a mounting screw 67, and the other end is fixed to the end surface of the end plate 46 of the fixed scroll body 45 via a mounting screw 68.

The head of the above-mentioned mounting screw 68
...located within.

The end face of the end plate 46 of the fixed scroll main body 45 and the cover 2
The receiver 3 is spaced apart from the end face of the hole 62 by a narrow gap, and is sealed by each seal ring 64, 65. This narrow space is formed as an intermediate pressure chamber 69.

By providing the leaf spring 66 and the intermediate pressure chamber 69, the fixed scroll main body 45 is supported by the cover 23 so as to be freely displaceable in the thrust direction.

FIG. 2 shows a plan view of the assembled fixed scroll 6 with the fixed scroll main body 45 attached and fixed to the cover 23.

As shown again in FIG. 1, the wrap 49 of the fixed scroll main body 45 and the wrap 41 of the orbiting scroll 5 mesh with each other, and are surrounded by each other's wraps 4941 and end plates 46.39, forming a compressed section having a substantially crescent shape. A chamber 70 is formed.

The tip of each wrap 49° 41 is connected to the end plate 4 facing it.
6.39 It is assembled so that there is a narrow gap g between the end face and the end face.

An annular projection 5 provided integrally with the fixed scroll body 45
0 has the same protruding height as the above-mentioned wrap 49, so that its tip portion has a narrow gap p with the end surface of the end plate 39 of the orbiting scroll 5.

Note that the end plate 46 of the fixed scroll main body 45 is provided with communication holes 54 and 54 passing through both end surfaces thereof, so that the intermediate pressure chamber 69 and the compression chamber 70 communicate with each other through the communication hole 54. do.

The opening end face of the oil supply hole 015g provided from the peripheral surface of the end plate 46 of the fixed scroll main body 45 is closed by a blind plug 71. Oil supply hole El opened in the end face of this boss portion 47
From 5e to oil supply hole F15f.

Oil supply hole F15f with both ends closed and a pair of oil supply holes H
15h, an oil supply passage 72 extending from 15h to the compression chamber 70
is formed.

A backflow prevention means 73 is provided in the oil supply hole E15e, which is a midway portion of the oil supply passage 72. This is the snap ring 7 that fits into the snap ring groove 53.
4, an oil valve 75 superimposed on the snap ring 74, a valve chute 76, and a spring 77 that elastically biases the oil valve 75 and the valve chute 76 toward the snap ring 74. The oil valve 75 is connected to the oil supply hole E15e together with the snap ring 74.
It has a shape that blocks the. From these two points, only when pressure is applied to the oil valve 75 that overcomes the elastic force of the spring 74, the oil valve 75 opens the oil supply hole E15e.

Further, when a separate pressure is applied from the same direction as the elastic force of the spring 74, the oil valve 75 closes the oil supply hole E15e.

The support frame 7 has this peripheral surface and the engagement hole 13.
A tapered hole 78 is provided passing through the airtight case 1, and the end of a suction pipe 79 that is provided passing through the sealed case 1 is fitted into the tapered hole 78. This suction pipe 79 and the closed case 1 are sealed to maintain airtightness.

On the other hand, a discharge pipe 80 is provided at the upper end of the sealed case 1 and communicates with the interior thereof.

An oil reservoir 81 in which lubricating oil collects 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 compression mechanism section 3 is immersed in the lubricating oil in the oil reservoir section 81.

A rotor 82 constituting the electric motor section 4 is fitted into the rotor shaft section 28 of the main shaft 18 that protrudes from the bearing section 8 of the support frame 7 . A thrust ring 83 is provided between the lower end surface of the rotor 82 and the end surface of the bearing portion 8 of the support frame 7.
A wave washer 84 is interposed to receive the load of the main shaft 18 in the thrust direction.

As shown in FIG. 19, the thrust ring 83 has a circular outer periphery, and is provided with a fitting hole 84 that is partially flat so that it can fit into the rotor shaft portion 28 of the main shaft 18. A pair of oil escapes 85, 85 are provided in this fitting hole 84.

As shown again in FIG. 1, a disk 86 is fitted into the rotor 82 together with the rotor shaft 28, and this disk 86 protrudes from the upper end surface of the rotor 82.

A separation plate 87 is provided at the protruding upper end, and a discharge passage C30c is provided along the axis extending from the lower end to the vicinity of the upper end. A check valve 88 is provided at the lower end of the discharge passage C30c to prevent backflow of the discharge gas.

As shown in FIG. 20, the check valve 88 includes a plurality of legs 88b integrally projecting radially from a disc-shaped base 88a.

As shown in FIG. 1 again, a plurality of horizontal holes 89 are provided in the upper part of the disk 86, and the discharge passage C3
Connects with 0c.

A stator 90 constituting the electric motor section 4 is fitted onto the inner peripheral surface of the sealed case 1 . The inner circumferential surface of the stator 90 surrounds the outer circumferential surface of the rotor 82 with a narrow gap therebetween. Upper coil end 90 of the stator 90
A connection cord 91 extending from a is electrically connected to a terminal 92 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 18 is rotationally driven together with the rotor 82, and the orbiting scroll 5 engaged with the crank bin portion 29 makes an orbiting motion. The outer peripheral end side of the compression chamber 70 formed between the wrap 41 of the orbiting scroll 5 and the wrap 49 of the fixed scroll main body 45 becomes negative pressure, and refrigerant gas is sucked from the suction pipe 79. The refrigerant gas flows through the notch 55 of the annular protrusion 50 provided opposite to the suction pipe 79.
Then, it is guided to the compression chamber 70 via a notch 55 provided on the opposite side. The refrigerant gas is fed from the peripheral end of the compression chamber 70 toward the center and is compressed from the point where its volume becomes smaller. When it is sent to the compression chamber 70 at the center, the pressure increases to a predetermined high pressure.

The highly pressurized gas is then discharged from the discharge port 42 provided in the orbiting scroll 5, and passes through the check valve 88 provided in the disk 86 via the discharge passage B50b and the discharge passage A30a provided in the main shaft 18. Furthermore, it is discharged into the sealed case 1 from the discharge passage C30c and the side hole 89. That is, this compressor is a so-called high-pressure type compressor in which the closed case 1 is filled with high-pressure gas. Furthermore, the high pressure gas is discharged from the discharge pipe 80 and guided to a predetermined location.

By the way, at the time of startup, the end portions of the laps 41 and 49 of the orbiting scroll 5 and the fixed scroll main body 45 have narrow gaps g with the opposing end plates 46 and 39, so the suction is not performed from there. Some of the refrigerant gas leaks. In other words, due to the gap p, the starting load can be extremely small, and smooth starting can be achieved.

Simultaneously with this compression movement, the pressure in the compression chamber 70 rises to a level near the pressure determined by the number of turns of each wrap 41, 49, etc. Therefore, the orbiting scroll 5 and the fixed scroll main body 45 are subjected to a thrust direction load in mutually opposite directions and a radial direction load in a radial direction to the wrap 41°49 shape. As a result, the orbiting scroll 5 is placed in the thrust receiver 20 and the fixed scroll body 4
5 tries to be strongly pressed against the cover 23.

However, some of the gas that is being compressed in the compression chamber 70 passes through the communication holes 54 and 54 provided in the end plate 46 of the fixed scroll main body 45, and passes through the intermediate space formed between the fixed scroll main body 45 and the cover 23. It is guided into the pressure chamber 69. Since the cover 23 is fixedly attached to the support frame 7, it is not affected by the gas pressure introduced into the intermediate pressure chamber 69.

Since the fixed scroll main body 45 is supported by the cover 23 via the leaf spring 66, it receives back pressure in the anti-thrust direction due to the gas pressure introduced into the intermediate pressure chamber 69. That is, the fixed scroll main body 45 is pushed up by the back pressure in the anti-thrust direction that overcomes the thrust force with a very small time lag after startup, and the tip of each wrap 41.49 comes into contact with the end surface of the opposing end plate 39.46. gas leakage is regulated.

With the compression action, the pressure inside the sealed case 1 becomes high for a while, and the pressure is transferred from the crank chamber 37 to the end plate 3 of the orbiting scroll 5 through the gap between the thrust receiver 20 and the crank pin part 29.
9 as back pressure.

At the same time, it moves toward the fixed scroll 6 via the communication portion 27 provided in a portion of the ring frame 25 and the support frame 7, and acts as a back pressure on the cover 23 and the boss portion 47 of the fixed scroll main body 45.

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. Tatashi,
By applying this anti-thrust force, the orbiting scroll 5 does not have to be strongly pressed against the thrust receiver 20. That is, as the force in the opposite direction to the thrust force is applied, the sliding loss between the end plate 39 of the orbiting scroll 5 and the thrust receiver 20 is significantly reduced, and the orbiting scroll 5 makes a smooth orbiting motion. This anti-thrust force can be arbitrarily set by changing the inner diameter area of the thrust receiver 20 and the total area of the oil groove C32c.

On the other hand, in the fixed scroll 6, since the cover 23 is fixed to the support frame 7, the back pressure accompanying the high pressure inside the closed case 1 affects only the boss portion 47 of the fixed scroll main body 45. In the fixed scroll main body 45, as described above, back pressure is also present in the intermediate pressure chamber 69, and the resultant force of this back pressure and the back pressure applied to the boss portion 47 is generated. 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 45
It is the force applied to Naturally, the resultant force of the anti-thrust force is larger, and the fixed scroll main body 45 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 45 is caused by the reaction in the intermediate pressure chamber 69 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 70 should be maintained.

■ The force relationship that acts on the fixed scroll main body 45 and the orbiting scroll 5 is as follows: The thrust force that acts on the fixed scroll main body 45 is exerted on the carbos portion 47, and the thrust force that acts on the anti-thrust car compression chamber 69 acts on the anti-thrust car compression pressure chamber 69. - (A) To obtain the relationship between thrust force acting on the orbiting scroll 5 due to Kerr compression> anti-thrust force acting on the end plate 39.

Then, the force acting on the fixed scroll main body 45 and the orbiting scroll 5 is the above formula (A) + thrust force acting on the orbiting scroll 5 due to compression> anti-thrust force acting on the end plate 39, and eventually the boss of the fixed scroll main body 45 Anti-thrust force acting on portion 47 + anti-thrust force acting on intermediate pressure chamber 69>An anti-thrust force acting on end plate 39 of orbiting scroll 5.

As described above, a load is applied to each of the wraps 41 and 49 in the radial direction as a result of the compression movement. In particular, since the fixed scroll main body 45 is supported by the cover 23 via the leaf spring 66, the wrap 49 receives a force in the radial direction and is tilted by a very small amount with respect to the axis.

The amount of fall of the wrap 49 depends on the fitting state of the sliding portion of the fixed scroll main body 45, but it is directly related to which part of the orbiting scroll 5 is in contact with the wrap 41, or the magnitude of the contact load. do. If the contact portion is far away from the axis and in contact over the entire circumference, it will be more difficult to fall. Further, it is natural that the contact portion is less likely to fall down if the distance in the axial direction is smaller with respect to the point of application of the radial load.

The mirror plate 46 of the fixed scroll main body 45 is provided with an annular projection 50 along its peripheral edge.

Since the protruding height of the annular protrusion 50 is set to be exactly the same as the protruding height of the wrap 49, the tips of each protrusion come into contact with the end surface of the end plate 39 of the orbiting scroll 5 during compression except when starting. As a result, the annular protrusion 50 can minimize the fall of the fixed scroll main body 45, eliminate strong local contact with the wrap 49, and maintain extremely stable compression operation.

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

The lubricating oil in the oil reservoir 81 flows from the oil supply hole Al 5a of the support frame 7 to the crank chamber 37 as the main shaft 18 rotates.
The pump 35 rotates there, and the centrifugal force is applied to the outer periphery of the sample and the sample is blown away. And oil supply hole B15
b is led to an oil groove A32a provided on the circumferential surface of the main shaft portion 19 of the main shaft 18 via an oil supply hole C15c. therefore,
Smooth sliding between the main shaft portion 19 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 19 and the thrust ring 83.

Further, a portion of the lubricating oil from the oil supply hole C15c communicates with the oil supply hole D15d provided in the crank pin portion 28, and from the oil groove B52b on the circumferential surface of the engagement hole 31 to the ring groove 33. Therefore, the crank pin portion 29 and the orbiting scroll 5
ensure smooth sliding with the boss portion 40 of the oil guide horizontal hole 3.
4 and is accelerated by centrifugal force and discharged into the crank chamber 37.

From this crank chamber 37, the oil groove C3 of the thrust receiver 20
2c, the thrust receiver 20 and the orbiting scroll 5
ensure smooth sliding with the mirror plate 39. The oil is then returned from the drain passage A38a to the original oil reservoir 81 via a drain passage B58b provided in the support frame 7.

Next, oil supply to the compression chamber 70 will be explained.

Immediately after startup, the pressure inside the sealed case 1 is lower than the intermediate pressure of the compression chamber 70, so the gas in the compression chamber 70 flows into the oil supply hole H15h.
The oil tends to leak into the sealed case 1 through the oil supply passage 72. However, the oil valve 75 and the valve seat 76 are located in the oil supply hole E15e, which is the middle part of the oil supply passage 72.
A backflow prevention means 73 consisting of a spring 77 and the like is provided to prevent backflow of gas. Therefore, pressure loss can be minimized and compression efficiency can be increased.

When the pressure inside the sealed case 1 becomes slightly higher than the intermediate pressure of the compression chamber 70, the discharge side pressure is reduced to the oil valve 7.
5 by overcoming the spring 77 and spreading out the valve seat 7.
Lubricating oil is introduced into the oil supply hole F15f from the passage in the center of the hole F15f. This lubricating oil is supplied to the compression chamber 70 through the oil supply hole 015g and the oil supply hole H15h, ensuring smooth orbiting movement of the orbiting scroll 5 relative to the fixed scroll body 45.

[Effects of the Invention] As explained above, according to the present invention, a fixed scroll is constructed from 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. This allows smooth startup by reducing frictional resistance during startup. In addition, during compression operation immediately after startup, the gap between the wrap tip of each scroll and the end plate is close to zero, which has the effect of minimizing the amount of compression leakage from these gaps and achieving high compression efficiency. .

Further, according to the present invention, an annular projection is provided along the peripheral edge of the end plate of the fixed scroll main body, protruding at the same height as the wrap, and having a notch for fluid conduction in a part.
Even if the wrap of the fixed scroll main body is subjected to a load in the radial direction, the tip of the annular projection contacts the orbiting scroll over the entire circumference to prevent it from falling down, resulting in stable compression operation.

Further, according to the present invention, the oil reservoir in the inner bottom of the sealed case and the compression chamber are communicated through the oil supply passage, and a backflow prevention device is provided in the middle of the oil supply passage to prevent backflow of fluid from the compression chamber to the oil reservoir. Since the means is provided, it is possible to prevent fluid from leaking from the compression chamber especially when the internal pressure of the closed case is low such as during startup, thereby achieving high compression efficiency.

[Brief explanation of the drawing]

The drawings 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,
Figure 3 is a top view of the support frame, Figure 4 is IV of Figure 3.
- Longitudinal cross-sectional view along line IV, Figure 5 is a bottom view of the support frame, Figure 6 is a bottom view of the main shaft, Figure 7 is a side view of the main shaft with a part of the vertical section, and Figure 8 is its top view. Figure 9 is a partially omitted side view of the main shaft with a cross section taken at a different plane from Figure 7;
Fig. 10 is a bottom view of the orbiting scroll, Fig. 11 is a vertical sectional view thereof, Fig. 12 is a top view thereof, Fig. 13 is a bottom view of the fixed scroll main body, and Fig. 14 is XIV-XI of Fig. 13.
A vertical sectional view taken along the V line, FIG. 15 is a top view of the fixed scroll main body, FIG. 16 is a bottom view of the cover, and FIG. 17 is a top view of the fixed scroll body.
FIG. 18 is a top view of the cover, and FIG. 19 is a plan view of the cover. 7-'''1... Sealed case, 5... Orbiting scroll, 6... Fixed scroll, 70... Compression chamber, 3...
・Scroll type compression mechanism section, 4... Electric motor section, 39.
...End plate (of the orbiting scroll), 41...Wrap (of the orbiting scroll), 46...End plate (of the fixed scroll body), 49...Wrap (of the fixed scroll body),
47...Boss part (of the fixed scroll body), 45...
・Fixed scroll body, 54...Communication hole, 69...
Intermediate pressure chamber, 23... Cover 50... Annular projection, 8
DESCRIPTION OF SYMBOLS 1... Oil reservoir part, 72... Oil supply passage, 73... Backflow prevention means. Applicant's representative Patent attorney Takehiko Suzue 16 Figure 1B Figure 23 Sword V- / 17th Ward No. 191! ! Figure 20

Claims (3)

[Claims] (1) A hermetic case, a scroll-type compression mechanism part housed in the lower part of the hermetic case and forming a compression chamber by meshing an orbiting scroll and a fixed scroll, and a scroll-type compression mechanism part connected to the upper part of the scroll-type compression mechanism part. It is equipped with an electric motor section,
In a high-pressure scroll compressor that discharges high-pressure gas compressed in the compression chamber of the scroll-type compression mechanism into a closed case, the orbiting scroll receives back pressure from the high-pressure gas discharged into the closed case. The fixed scroll consists of an end plate, and a spiral wrap integrally provided on the end plate, and the fixed scroll includes an end plate whose one end face has a narrow gap with the wrap of the orbiting scroll, and a spiral wrap integrally provided on the end face of the end plate. a wrap whose tip portion is provided on the end plate of the orbiting scroll and which has a narrow gap and meshes with the wrap of the orbiting scroll to form a compression chamber with each other; a sealed case integrally provided on the other end side of the end plate; An airtight space is provided between a fixed scroll main body consisting of a boss section which receives back pressure from high pressure gas discharged inside the fixed scroll main body, and the end plate of the fixed scroll main body, which supports the fixed scroll main body so as to be freely displaceable in the thrust direction. 1. A scroll compressor comprising a cover defining an intermediate pressure chamber, and the compression chamber and the intermediate pressure chamber communicate with each other through a communication hole formed in an end plate of a fixed scroll body. (2) The fixed scroll main body is provided with an annular protrusion along the peripheral edge of the end plate, which is separate from the wrap, projects at the same height as the wrap, and has a notch for fluid conduction in a part. Scroll compressor according to claim 1, characterized in that: (3) The sealed case has an oil reservoir in its inner bottom that collects lubricating oil, communicates this oil reservoir with the compression chamber through an oil supply passage, and has a compression chamber in the middle of the oil supply passage. 2. The scroll compressor according to claim 1, further comprising backflow prevention means for preventing backflow of compressed fluid from the fluid to the oil reservoir.