JPH04171289A - Scroll compressor - Google Patents

Abstract

PURPOSE:To prevent a thrust surface from being worn by canceling the downward force of an electromotive element by back pressure which works upon the back surface of a scroll end plate against the downward force by an electromagnetic force of the electromotive element which works upon a scroll compression element and a dead load of the electromotive element. CONSTITUTION:On a rotor 5 during operation, load occurs in a thrust direction by an electromagnetic force works on in the downward direction of an axial direction and a dead load of the rotor. The second scroll is pressed against an auxiliary frame 9. A hollow chamber 11 communicates with an inlet pipe 14 and forms a low-pressure chamber. Because the inside area of a sealing material 33 is bigger than that of a sealing material 32, a force which presses the second scroll 16 is bigger than a force which presses the first scroll 15. A thrust load generated at the rotor 5 is canceled by the difference in the pressure which works upon the second scroll 16 and the first scroll 15, so it is thus possible to make surface pressure of the thrust bearing surface of the second scroll 16 smaller and prevent wear at the time of input lifting and thrust bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application This invention relates to a scroll compressor that performs compression by rotating both scrolls in the same direction.

(b) Prior art A conventional scroll fluid machine is, for example,
The structure is as shown in Japanese Patent No. 190. Here, a conventional example will be explained with reference to this publication. In FIG. 4, reference numeral 50 denotes a drive scroll disposed at the top, a spiral wrap 52 is provided on an end plate 51, and a discharge port 53 is provided integrally or fixedly at the center of the shaft. 54 is an exhaust path communicating with the discharge port 53 via a valve 55, 56 is a plurality of discharge holes drilled in the radial direction, 57 is a driven scroll disposed below, and a spiral wrap provided on the end plate 58. 59 is combined with the wrap 52 of the drive scroll 50, and a boss portion 60 is protruded from the lower part. 6
1 is a cylindrical container, 62 is a suction chamber, 63 is a bearing housing attached to the lower end of the container 61, supports the driven scroll 57 via a bearing 64, and is connected to the container 61 by a bolt 65 via an O-ring 66. Installed airtight. 6
Reference numeral 7 denotes an upper housing that is airtightly attached to the upper end of the container 61 with a bolt 68 via an O-ring 69, and an annular atmospheric pressure chamber 70 is formed on the outer periphery of the upper housing.
An exhaust lower 1 is opened from this atmospheric pressure chamber to communicate with the atmosphere. A drive shaft 73 72 is fitted into the upper housing 67.
A bearing 74 is a presser, which is fixed to the upper housing 67 with a screw 75, and supports the bearing 72.

76 and 77 are seals, 78 are retaining rings that support the seal 76 fixed to the upper housing 67, and 79 are upper containers that are fixed to the upper housing 67 and the container 61 with bolts 68, to which the exhaust lower 1 is attached. There is. Reference numeral 80 denotes an electric motor as a driving source, which is attached to the upper container 79 via a flange 81 with bolts 82 . Reference numeral 83 denotes a rotating shaft of the electric motor 80, which is connected to the drive shaft 73 by a shaft coupling 84.

85 is a suction port attached to the container 61 for evacuating the object to be evacuated, and 86 is a spring that presses the valve 55. 87 is a joint, which is positioned by a key or protrusion 88 and a rub 89 provided on the drive scroll 50. In addition, the love 89 has a bolt 90 attached to the driven scroll 57.
Fixed by

Further, the drive scroll 50 side freely slides in a groove 91 provided in the joint 87.
- 92 is a check valve that is pressed against the oil suction pipe 93 by a leaf spring 94; 95 is an oil passage, an O ring 96 and a seal 76
．． 77, it is sealed with the atmospheric pressure chamber 70. 97 is oil.

In the scroll fluid machine with this structure, the driving scroll 5
0 and the driven scroll 57 by the joint 87 and the love 89.
It is rotated at an 80° twisted position, and the gas for evacuating the object to be evacuated is sucked in from the suction port 85 and passed through the exhaust path 54, the discharge hole 56, and the atmospheric pressure chamber 70 to the exhaust lower 1.
At the same time, oil 97 is supplied from the oil passage 95 to the contact surface between the driving scroll 50 and the driven scroll 57 during operation to prevent the atmosphere from entering the suction port 85.

(8) Problems to be Solved by the Invention However, in the conventional scroll fluid machine, the dead weight of the rotor of the electric motor 80 and the electromagnetic force due to the skew of this rotor act on the drive scroll 50, and this downward force is applied to the drive scroll. 50 acts on the thrust receiver of the driven scroll 51, the thrust load applied to the thrust receiver of the driven scroll 51 increases, the input increases, and there is a problem that wear occurs on the thrust receiver.

This invention solves the above-mentioned problem, and aims to provide a scroll compressor in which the electromagnetic force of the electric element that acts as a thrust load is canceled out by the pressure applied to the back side of the end plate of the roll of the sufu. It is something.

(2) Means for Solving the Problem This invention houses an electric element on the upper side and a scroll compression element on the lower side in a closed container, and the scroll compression element is
a first scroll having a shaft connected directly or indirectly to an electric element by erecting a spiral wrap on an end plate; and a shaft eccentric to the center of the shaft of the first scroll; A second scroll has a spiral wrap erected on an end plate that engages with the first scroll, and while rotating this second scroll in the same direction as the first scroll, the first and second scrolls are rotated in the same direction as the first scroll. an Oldham joint that performs compression by gradually reducing a plurality of compression spaces formed by the scroll from the outside to the inside; a main frame having a main bearing that pivotally supports the shaft of the first scroll; It consists of an auxiliary frame having an auxiliary bearing that pivotally supports the shaft of the second scroll, and the space formed inside by these frames becomes a low pressure chamber, and the first and second scrolls are
In a scroll compressor that accommodates a scroll, the back pressure acting on the back surface of the end plate of the first scroll and the second scroll is made smaller on the first scroll side than on the second scroll side. .

(*) Effect This invention is constructed as described above, so that it counteracts the downward force caused by the electromagnetic force of the electric element acting on the scroll compression element and the own weight of this electric element, and acts on the back surface of the end plate of the scroll. The downward force of the electric element is canceled out by the renal blood force.

Example) The present invention will be explained below based on the example shown in FIGS. 1 and 2.

1 is a closed container, inside this container there is an electric element 2 on the upper side,
The scroll compression elements 3 are fully housed on the lower side. The electric element 2 consists of a stator 4 and a rotor 5 disposed inside the stator. An air gap 6 is formed between the stator 4 and the rotor 5. 7 is a main frame, and a main bearing 8 is provided in the center of this frame. Reference numeral 9 denotes an auxiliary frame, and this auxiliary frame is provided with an auxiliary bearing portion 10 eccentric to the main bearing 8 of the main frame 7. A cylindrical frame 12 is fixed with bolts 13 between the main frame 7 and the auxiliary frame 9 so as to form a hollow chamber 11 inside.

This hollow chamber communicates with the suction pipe 14 and forms a low pressure chamber.

The scroll compression element 3 is composed of a first scroll 15 driven by the electric element 2 and a second scroll 16 rotated in the same direction as the first scroll. The first scroll 15 includes a disc-shaped end plate 17, a spiral wrap 18 made of an involute curved line erected on one side of the end plate, and a spiral wrap 18 projecting from the center of the other side of the end plate 17. Drive shaft 1 inserted and fixed into rotor 5
It consists of 9. And the first scroll 15
constitutes the drive side scroll. The second scroll 16 includes a disk-shaped end plate 20, a spiral wrap 21 made of an involute curved line erected on one side of the end plate, and a spiral wrap 21 projecting from the center of the other side of the end plate 20. It is composed of a driven shaft 22. The second scroll 16 constitutes a driven scroll.

The first scroll 15 has a drive shaft 19 supported by a main bearing 8 of the main frame 7, and the second scroll 16 has a driven shaft 22 supported by an auxiliary bearing 10 of an auxiliary frame 9. The wraps 18,21 are interlocked facing each other within the cavity 11 so as to form a plurality of compression spaces 23 therein.

The drive shaft 19 is provided with a discharge hole 25 for discharging the refrigerant compressed within the compression space 23 into a space 24 between the electric element 2 and the scroll compression element 3 within the closed container 1.

27, and a first key 29 that is fitted into a first key groove 28 provided on the outer periphery of the end plate 17 of the first scroll 15.
and a second key 31 that is fitted into a second key groove 30 provided on the outer periphery of the end plate 20 of the second scroll 16. And the Oldham joint 26 is the key 29
．． By sliding 31 in the keyway 28.30,
The first and second scrolls 15, 16 are made to swing relative to each other.

32 is a sealing material provided between the main frame 7 and the mirror plate 17, and inside this sealing material are the main bearing 8 and the drive shaft 19.
The high pressure in the space 24 acts through the sliding surface. 3
3 is a sealing material provided between the auxiliary frame 9 and the end plate 20, and the high pressure of the space 24 acts on the inside of this sealing material via the sliding surface of the auxiliary bearing 10 and the driven shaft 22. . The inner area of the sealing material 33 is larger than the inner area of the sealing material 32 and is deformed.

34 is a discharge pipe, and this discharge pipe is provided in the earthen wall of the closed container 1.

In the scroll compressor configured in this manner, when the electric element 2 is rotated, its rotational force is transmitted to the first scroll 15 via the drive shaft 19. The rotational force transmitted to the first scroll is transmitted to the second scroll 16 via the Oldham joint 26, causing the second scroll to rotate in the same direction as the first scroll 15.

The second scroll 16 rotates at a position eccentric to the center of the driven shaft 22 with respect to the center of the drive shaft 19 of the first scroll 15 . Therefore, the first scroll 15 and the second scroll 16 gradually reduce the compression space 23 formed by these scrolls from the outside to the inside, and the refrigerant flowing into the hollow chamber 11 from the suction pipe 14 is caused to flow into the outer compression space 23 and compressed.

This compressed refrigerant is transferred to the drive shaft 1 of the first scroll 15.
The liquid is discharged into the space 24 through the discharge hole 25 provided in the electric element 2, passes through the air gap 6 of the electric element 2, and is completely discharged from the discharge pipe 34 to the outside of the closed container 1.

During operation, a load in the thrust direction is generated on the rotor 5 due to the electromagnetic force acting downward in the axial direction and the rotor's own weight. The thrust load acts from the first scroll 15 to the second scroll 16 via the drive shaft 19, and presses the second scroll against the auxiliary frame 9.

Further, the sealing materials 32 and 33 allow high-pressure refrigerant in the space 24 to act on the inside of these sealing materials through the sliding surfaces of the main bearing 8 and the auxiliary bearing 10, and the first scroll 15 and the second scroll 16 to prevent the refrigerant compressed in the compression space 23 from leaking, and also to prevent the high-pressure refrigerant from leaking into the hollow chamber 11.

Since the area of the inside of the sealing material 33 is larger than that of the inside of the sealing material 32, the force that presses the second scroll 16 becomes larger than the force that presses the first scroll 15. Therefore, by canceling out the thrust load generated by the rotor 5 by the difference in the pressing forces acting on the second scroll 16 and the first scroll 15, the thrust bearing of the second scroll 16 is The surface pressure is kept small to prevent an increase in input power and wear on the thrust receiver.

This invention reduces the thrust load of the rotor 5 by the difference in back pressure acting on the back surfaces of the first and second scrolls 15 and 16.
By making the scroll compression element 3 narrower, an increase in input power and wear of the scroll compression element 3 can be prevented.

As shown in FIG. 3, two sealing materials 35 and 36 are provided between the first scroll 15 and the main frame 7, and two sealing materials 37 are provided between the second scroll 16 and the auxiliary frame 9.
．． 38, and a hole 39. is provided between these sealing materials.
It goes without saying that the same effect can be obtained even if different intermediate pressures are applied at 40.

(G) Effects of the Invention As described above, according to the present invention, the back pressure acting on the back surfaces of the end plates of the first scroll and the second scroll is
Since the first scroll side, on which the thrust load of the rotor acts, is made smaller than the second scroll side, the thrust load generated on the rotor can be reduced by the difference in back pressure between the second scroll and the first scroll. The second scroll thrust bearing is designed to reduce the surface pressure on the surface, reduce the input to the scroll compressor, and prevent wear on the thrust surface.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a scroll compressor showing one embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a main part of a scroll compression element, and FIG. 3 is an enlarged cross-sectional view of a main part showing another embodiment. ,
FIG. 4 is a sectional view of a conventional scroll fluid machine. 1... Airtight container, 2... Electric element, 3...
Scroll compression element, 7... Main frame, 8
...Main bearing, 9...Auxiliary frame, 10.
...Auxiliary bearing, 15...First scroll, 16
...Second scroll, 17.20...End plate,
18.21... Wrap, 19... Drive shaft,
22... Driven shaft, 26... Oldham joint, 3
2, 33, 35, 36° 37.38...Sealing material.

Claims (3)

[Claims] 1. A motorized element is housed in the upper part of the airtight container and a scroll compression element is stored in the lower part, and the scroll compression element is connected to a shaft that is directly or indirectly connected to the motorized element by erecting a spiral wrap on the end plate. a first scroll having;
having an axis eccentric to the center of the axis of the first scroll;
a second scroll having a spiral wrap erected on an end plate that faces and engages with the first scroll; and while rotating this second scroll in the same direction as the first scroll, the first and second scrolls are an Oldham joint that performs compression by gradually reducing a plurality of compression spaces formed by the scrolls from the outside to the inside; a main frame having a main bearing that pivotally supports the shaft of the first scroll; Second
and an auxiliary frame with an auxiliary bearing that pivotally supports the scroll shaft, and the space formed inside by these frames is used as a low pressure chamber, and the scroll compression chamber in which the first and second scrolls are housed. 1. A scroll compressor, characterized in that the back pressure acting on the back surfaces of the end plates of the first scroll and the second scroll is smaller on the first scroll side than on the second scroll side. 2. The first scroll is characterized in that the area on which back pressure acts on the back surfaces of the end plates of the first scroll and the second scroll is made smaller on the first scroll side than on the second scroll side.
A scroll compressor according to the claims. 3. Scroll compressor according to claim 1, characterized in that the back pressure acting on the back surfaces of the end plates of the first scroll and the second scroll is smaller on the first scroll side than on the second scroll side. .