JP2902770B2 - Scroll compressor - Google Patents

Description

The present invention relates to a scroll compressor that performs compression by rotating both scrolls in the same direction.

(B) Conventional technology A conventional scroll fluid machine is disclosed in, for example, Japanese Patent Application Laid-Open No. 64-2419.
It is configured as shown in Japanese Patent Publication No. 0. Here, a conventional example will be described with reference to this publication. In FIG. 4, reference numeral 50 denotes a drive scroll disposed at an upper portion, a spiral wrap 52 is provided on a head 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 arranged below, and a spiral wrap provided on a head plate 58 59 is combined with the wrap 52 of the driving scroll 50, and the boss portion is provided at the bottom.
60 have been issued. 61 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 64 and bolts to the container 61
It is airtightly attached by an O-ring 66 by 65.
Reference numeral 67 denotes an upper housing which is air-tightly attached to the upper end of a container 61 by bolts 68 via an O-ring 69, and has an annular atmospheric pressure chamber 70 formed on the outer periphery thereof. An exhaust port 71 is opened. 72 is a bearing that is fitted to the upper housing 67 and supports the drive shaft 73;
A holder 74 is fixed to the upper housing 67 by screws 75 and supports the bearing 72. 76 and 77 are seals, 78 is a retaining ring that supports the seal 76 fixed to the upper housing 67,
An upper container 79 is fixed to the upper housing 67 and the container 61 with bolts 68, and has an exhaust port 71 attached thereto. Reference numeral 80 denotes an electric motor as a driving source, which is mounted on an upper container 79 via a flange 81 by bolts 82. Reference numeral 83 denotes a rotating shaft of the electric motor 80, which connects the drive shaft 73 with a shaft coupling 84. 85 is a container
A suction port 86 attached to 61 and for evacuating the object to be evacuated is a spring and presses the valve 55. Reference numeral 87 denotes a joint, which is positioned by a key or projection 88 provided on the drive scroll 50 and a hook 89. Incidentally, the rod 89 is fixed to the driven scroll 57 by a bolt 90.

Further, the drive scroll 50 side slides freely in a groove 91 provided in the joint 87.

A check valve 92 is pressed against an oil absorbing pipe 93 by a leaf spring 94. An oil passage 95 is sealed from the atmospheric pressure chamber 70 by an O-ring 96 and seals 76 and 77. 97 is oil.

In the scroll fluid machine of this structure, the driving scroll
The joint 50 and the driven scroll 57 are rotated at a position twisted 180 ° by the joint 87 and the rod 89, and gas for evacuation from the object to be evacuated is sucked in from the suction port 85, and the exhaust path 54, the projecting hole 56, the large The oil is discharged from the exhaust port 71 to the atmosphere through the air pressure chamber 70, and the 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.
The air is prevented from entering.

(C) Problems to be Solved by the Invention However, in the conventional scroll fluid machine, the own weight of the rotor of the electric motor 80 and the electromagnetic force due to the skew of the rotor act on the drive scroll 50, and this downward force is applied to the drive scroll 50. Since the thrust load acts on the thrust receiver of the driven scroll 51 from 50, the thrust load applied to the thrust receiver of the driven scroll 51 increases, causing an increase in input and wear of the thrust receiver.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a scroll compressor in which electromagnetic force of an electric element acting as a thrust load is applied to the back of a scroll head plate to cancel out by pressure. It is.

(D) Means for Solving the Problems The present invention accommodates an electric element on the upper side and a scroll compression element on the lower side in an airtight container, and makes the scroll compression element stand up with a spiral wrap on a head plate. A first scroll having an axis directly or indirectly connected to the electric element, and a head plate having an axis eccentric to the center of the axis of the first scroll and meshing opposite to the first scroll. A second scroll in which a spiral rub is erected, and a plurality of compression spaces formed by the first and second scrolls being outwardly rotated while rotating the second scroll in the same direction as the first scroll. An Oldham coupling for gradually reducing and inwardly compressing from the inside, and a main frame having a main bearing for supporting the shaft of the first scroll,
And an auxiliary frame having an auxiliary bearing for supporting the axis of the second scroll. The space formed inside the frame by the frame is used as a low-pressure chamber and the first and
In the scroll compressor accommodating the second scroll, 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. .

(E) Operation The present invention is configured as described above, and thus acts on the back surface of the scroll head plate with respect to the downward force due to the electromagnetic force of the electric element acting on the scroll compression element and the weight of the electric element. The back pressure negates the downward force of the electric element.

(F) Embodiment The present invention will be described below with reference to the embodiment shown in FIGS. 1 and 2.

Reference numeral 1 denotes a closed container in which an electric element 2
However, the scroll compression elements 3 are respectively housed in the lower side. The electric element 2 includes a stator 4 and a rotor 5 arranged inside the stator. Stator 4 and rotor 5
An air gap 6 is formed between them. Reference numeral 7 denotes a main frame, on which a main bearing 8 is provided at the center. Reference numeral 9 denotes an auxiliary frame, which is provided with an auxiliary bearing 10 eccentric to the main bearing 8 of the main frame 7. A cylindrical frame 12 is bolted between the main frame 7 and the auxiliary frame 9 so as to form a hollow chamber 11 inside.
Fixed at 13. The hollow chamber communicates with the suction pipe 14 to form a low-pressure chamber.

The scroll compression element 3 includes a first scroll 15 driven by the electric element 2 and a second scroll 16 that rotates in the same direction as the first scroll. The first scroll 15 has a disk-shaped end plate 17, a spiral wrap 18 formed of an involute-shaped curve erected on one surface of the end plate, and a center of the other surface of the end plate 17. And a drive shaft 19 inserted and fixed to the rotor 5. The first scroll 15 constitutes a driving scroll. The second scroll 16 has a disk-shaped end plate 20, a spiral wrap 21 formed of an involute-shaped curve erected on one surface of the end plate, and protruding from the center of the other surface of the end plate 20. And a driven shaft 22. The second scroll 16 constitutes a driven scroll.

The first scroll 15 is supported on the drive shaft 19 by the main bearing 8 of the main frame 7, and the second scroll 16 is
The driven shaft 22 is supported by the auxiliary bearing 10 of the
The six wraps 18 and 21 face each other in the hollow chamber 11 so as to engage with each other, so that a plurality of compression spaces 23 are formed therein.

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

Reference numeral 26 denotes an Oldham coupling provided between the first and second scrolls 15 and 16. The Oldham coupling includes a ring 27 provided on the outer periphery of the wraps 18 and 21 and a head plate 17 of the first scroll 15. A first key 29 fitted to a first key groove 28 provided on the outer periphery, and a second key fitted to a second key groove 30 provided on the outer periphery of the end plate 20 of the second scroll 16. 31
It is composed of And Oldham fitting 26 is key 2
By sliding 9 and 31 in the keyways 28 and 30,
The second scrolls 15 and 16 relatively swing.

Reference numeral 32 denotes a seal member provided between the main frame 7 and the end plate 17, and a high pressure in the space 24 acts on the inside of the seal member via a sliding surface between the main bearing 8 and the drive shaft 19. . Reference numeral 33 denotes a seal member provided between the auxiliary frame 9 and the end plate 20, and a high pressure in the space 24 acts on the inside of the seal member via a sliding surface between the auxiliary bearing 10 and the driven shaft 22. . The area inside the seal member 33 is formed larger than the area inside the seal member 32.

Reference numeral 34 denotes a discharge pipe, which is provided on the upper wall of the closed container 1.

In the scroll compressor configured as described above, when the electric element 2 is rotated, the rotational force is transmitted to the first scroll 15 via the drive shaft 19. The torque transmitted to the first scroll is transmitted to the second scroll through the Oldham coupling 26.
The second scroll is rotated in the same direction as the first scroll 15. The second scroll 16 rotates at a position where the center of the driven shaft 22 is eccentric 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. Flows into the outer compression space 23 and is compressed. The compressed refrigerant protrudes into the space 24 from the discharge hole 23 provided in the drive shaft 19 of the first scroll 15 and passes through the air gap 6 of the electric element 2 to discharge the refrigerant.
It is discharged from the closed container 1 from 34.

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 weight of the rotor. The thrust load acts on the second scroll 16 from the first scroll 15 via the drive shaft 19,
The second scroll is pressed against the auxiliary frame 9.

Further, the seal members 32 and 33 allow the high pressure refrigerant in the space 24 to act on the main bearing 8 via the sliding surface with the auxiliary bearing 10 inside the seal members, thereby the first scroll 15 and the second scroll 16 to prevent the refrigerant compressed in the compression space 23 from leaking and to prevent the high-pressure refrigerant from leaking into the hollow chamber 11.

Since the area inside the seal member 33 is larger than the area inside the seal member 32, the force pressing the second scroll 16 is larger than the force pressing the first scroll 15. Therefore, the thrust load generated by the rotor 5 is the second
The pressure is reduced by the difference between the pressing forces acting on the scroll 16 and the first scroll 15, so that the surface pressure of the thrust receiving surface of the second scroll 16 is reduced, thereby increasing the input and abrasion of the thrust receiving. Is not generated.

The present invention reduces the thrust load of the rotor 5 by the difference between the back pressures acting on the back surfaces of the first and second scrolls 15 and 16 so that the input of the scroll compression element 3 can be prevented from rising and abrasion can be prevented. It was done.

As shown in FIG. 3, between the first scroll 15 and the main frame 7, two seal members 35, 36 and a second scroll 1 are provided.
A similar effect can be obtained by providing two sealing materials 37, 38 between the auxiliary frame 9 and 6 and applying intermediate pressures having different pressures to the small holes 39, 40 between these sealing materials. Needless to say.

(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 reduced by the first scroll side on which the thrust load of the rotor acts. Is smaller than the second scroll side,
A thrust load generated in the rotor can be canceled by a difference in back pressure between the second scroll and the first scroll,
The surface pressure of the thrust receiving surface of the second scroll is reduced, so that the input of the scroll compressor can be reduced, and the abrasion of the thrust surface can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a scroll compressor showing one embodiment of the present invention, FIG. 2 is an enlarged sectional view of a principal part of the scroll compression element, and FIG. 3 is an enlarged sectional view of a principal part showing another embodiment. ,
FIG. 4 is a sectional view of a scroll fluid machine showing a conventional example. DESCRIPTION OF SYMBOLS 1 ... Closed container, 2 ... Electric element, 3 ... Scroll compression element, 3 ... Main frame, 8 ... Main bearing, 9 ... Auxiliary frame, 10 ... Auxiliary bearing, 15 ... First scroll ,
16 second scroll, 17,20 mirror plate, 18,21 wrap, 19 drive shaft, 22 driven shaft, 26 Oldham coupling, 32,33,35,36,37, 38 …… Seal material.

Claims (3)

(57) [Claims] An electric element is accommodated on the upper side in a closed container and a scroll compression element is accommodated on a lower side, and the scroll compression element is directly or indirectly attached to the electric element by forming a spiral wrap on a head plate. A first scroll having a shaft connected thereto, and a spiral wrap standing on a mirror plate having a shaft eccentric to the center of the shaft of the first scroll and facing the first scroll. And a plurality of compression spaces formed by the first and second scrolls gradually reduced inward from the outside while rotating the second scroll in the same direction as the first scroll. An Oldham coupling that compresses the main frame, a main frame having a main bearing that supports the shaft of the first scroll,
And an auxiliary frame having an auxiliary bearing for supporting the axis of the second scroll. The space formed inside the frame by the frame is used as a low-pressure chamber and the first and
In the scroll compressor accommodating the second scroll, 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. And scroll compressor. 2. An apparatus according to claim 1, wherein the area of the back surface of the end plate of the first scroll and the second scroll on which the back pressure acts is smaller on the first scroll side than on the second scroll side. The scroll compressor described in 1. 3. The first scroll according to claim 1, wherein 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.
A scroll compressor according to claim 1.