JPH08200246A - Scroll type compressor - Google Patents

Abstract

PURPOSE: To provide a stable turn motion mechanism with compression efficiency improved, by preventing gas leakage and uneven wearing a chip seal due to swell rotating a turn scroll caused by unbalance of a pressure just after starting rotating a scroll type compressor. CONSTITUTION: Relating to a scroll type compressor, it is formed by arranging vertically a compression part 2 and an electric motor 3 in a sealed vessel 1 and by constituting the compression part of, a volute-shaped fixed scroll 4, turn scroll 5 forming this fixed scroll and a plurality of compression chambers 9, shaft 10 supporting a turn drive shaft 5c to form a crankshaft in an upper end and turned to be driven, and a bearing 7 journalling a crankshaft 11. Accordingly, a back pressure chamber 6 and an annular groove 5d are formed by conforming the center to the center of a lap of the turn scroll in a back surface of the turn scroll, and a chip seal 8 is fitted to this groove to turn the turn scroll in pressure contact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type compressor, and more particularly, to a structure for preventing gas leakage and uneven wear of a tip seal due to unstable waviness of an orbiting scroll.

[0002]

2. Description of the Related Art A conventional scroll type compressor will be described with reference to FIG. 4 which is a vertical sectional view thereof and FIG. 5 which is an enlarged sectional view of an essential part thereof. The scroll type compressor has a compression unit 2 and an electric motor 3 built in a sealed container 1, and the compression unit 2 includes a fixed scroll 4, an orbiting scroll 5, and an Oldham ring 1.
2, the crankshaft 11, the eccentric bearing 13, the bearing 7, and the shaft 10 are mainly configured. In this structure, a fixed scroll wrap 4b having a spiral shape is integrally formed on the fixed end plate 4a, the fixed scroll fixed to the bearing, the fixed scroll wrap 5b having a spiral shape on the orbiting end plate 5a, and the orbiting drive shaft 5c on the back surface. A plurality of compression chambers 9 are meshed with the orbiting scroll integrally formed with the scroll wrap inside.
Is formed. When the electric motor rotates, the orbiting scroll causes the orbiting scroll to orbit by the Oldham ring through the eccentric bearing fitted to the crankshaft formed in the upper part of the shaft attached to the bearing, while preventing rotation by the Oldham ring.
The low-pressure refrigerant sucked from the suction pipe 15 into the compression portion by the orbiting motion of the orbiting scroll is compressed while moving from the outer peripheral portion to the central portion of the compression chamber to become the high-pressure refrigerant, and the discharge port 14
Is discharged from the discharge pipe 19 through the discharge chamber 16, the communication passage 18, and the space 17 between the compression unit and the electric motor. Also,
Due to the refrigerant pressure rising in the central portion of the compression chamber, a releasing force that pushes down the orbiting scroll 5 acts, and a gap is formed between the fixed end plate 4a and the orbiting scroll wrap 5b and between the orbiting end plate 5a and the fixed scroll wrap 4b to cause gas leakage. In order to prevent the compression efficiency from decreasing, the high pressure refrigerant is introduced between the central portion of the rear surface of the swivel end plate 5a and the upper surface of the crankshaft.
On the other hand, a low pressure back pressure chamber 6 is provided on the outer periphery of the back surface, and a chip seal 8 for preventing the leakage of the high pressure refrigerant is provided in the middle of the back pressure chamber 6 on the pressure contact surface 7a of the bearing and pressed against the back surface of the orbiting scroll. As a result, the airtightness of the compression chamber is maintained against the separation force by the pushing force of the high-pressure refrigerant. However, at the start of the operation when the refrigerant pressures on the suction side and the discharge side are almost equal, the pressure in the compression chamber rises first, and then the pressure in the sealed container rises from the discharge chamber, so the pressure balance inside the fuselage is not balanced. . At this time,
As shown in FIG. 6, the orbiting force transmitted from the crankshaft acting on the orbiting drive shaft is divided into a force that rotates orthogonal to a force that presses the orbiting scroll wrap in the orbiting radial direction, and a reaction of this pressing force. The point is the orbiting scroll wrap that constitutes the compression chamber, and the action point (right arrow) and the reaction point (left arrow) are separated from each other in the axial direction of the orbiting drive shaft, so that a twisting moment acts on the orbiting end plate and tilts. . For this reason, there is a problem that undulating rotation occurs in the swivel end plate, gas leakage occurs in the compression chamber, and compression efficiency decreases, and at the same time, abnormal sliding occurs in each sliding portion and uneven wear of the tip seal occurs. there were.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art by a mechanism for preventing uneven wear of the tip seal for keeping the back pressure chamber on the back of the orbiting scroll at a low pressure. , To provide a scroll type compressor with improved stable operation performance and reliability.

[0004]

In order to achieve the above object, a compression part and an electric motor are arranged vertically in a hermetically sealed container, and the compression part meshes with a spiral fixed scroll and the fixed scroll. An orbiting scroll that collectively forms a plurality of compression chambers, and a shaft that supports the orbiting drive shaft of the orbiting scroll and forms a crankshaft at the upper end to orbitally drive the orbiting scroll,
In a scroll compressor constituted by a bearing that pivotally supports the crankshaft, a back pressure chamber is formed on the back surface of the orbiting scroll, and the end plate of the orbiting scroll on the pressure contact surface between the bearing and the orbiting scroll. An annular groove is provided on the back surface of the, and a tip seal is fitted in the groove to rotate the orbiting scroll under pressure. Further, the center of the annular groove is made to coincide with the center of the wrap of the orbiting scroll. Further, the cross-sectional shape of the groove is substantially U-shaped. On the other hand, the tip seal is substantially annular. The outer periphery of the tip seal is pressed against the outer periphery of the groove portion. Also,
The cross section of the tip seal is substantially trapezoidal. Further, a gap is provided between the inner circumference of the tip seal and the inner circumference of the groove. A gap is provided between the inside of the tip seal and the bottom of the groove.

[0005]

According to the above construction, the compression part and the electric motor are arranged vertically in the sealed container, and the compression part is engaged with the spiral fixed scroll and the fixed scroll to form a plurality of compression chambers. A scroll-type compressor formed of a orbiting scroll to be formed, a shaft for orbiting and driving a orbiting drive shaft of the orbiting scroll to form a crankshaft at the upper end, and a bearing for pivotally supporting the crankshaft, A back pressure chamber is formed on the back surface of the orbiting scroll, and an annular groove is provided on the back surface of the end plate of the orbiting scroll on the pressure contact surface of the bearing and the orbiting scroll. The scroll is rotated by pressing, and the center of the annular groove is made to coincide with the center of the wrap of the orbiting scroll, and the cross section of the groove is The shape is substantially U-shaped, while the tip seal is substantially annular, and the outer circumference of the tip seal is in pressure contact with the outer circumference of the groove portion, and the cross-sectional shape of the tip seal, The trapezoid has a substantially trapezoidal shape, and a gap is provided between the inner periphery of the tip seal and the inner periphery of the groove, and a gap is provided between the inside of the tip seal and the bottom of the groove. So
It is possible to prevent uneven wear of the tip seal for keeping the back pressure chamber on the back of the orbiting scroll at a low pressure.

[0006]

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same parts as those in the conventional example are denoted by the same reference numerals. FIG. 1 is a vertical cross-sectional view of a scroll type compressor showing an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part thereof. A compression unit 2 and an electric motor 3 are arranged vertically inside a sealed container 1, and the compression unit is provided with a scroll-shaped fixed scroll 4 and an orbiting scroll 5 that meshes with the fixed scroll to form a plurality of compression chambers 9. A shaft 10 for orbiting by forming a crankshaft 11 on the upper end of an orbiting drive shaft 5c of the orbiting scroll, and a bearing 7 for supporting the crankshaft.
And form a scroll compressor. In this structure, a fixed scroll wrap 4b having a spiral shape is integrally formed on the fixed end plate 4a, and a fixed scroll pressed against a bearing and a fixed scroll wrap 5 having a spiral shape on the swivel end plate 5a.
A plurality of compression chambers 9 are formed by meshing b with the orbiting scroll having the orbiting drive shaft 5c integrally formed on the back surface with the scroll wrap inside.

Now, description will be made with reference to FIG. A back pressure chamber 6 communicating with the low pressure side is formed on the outer peripheral back surface of the orbiting end plate of the orbiting scroll. Further, a high-voltage section 20 communicating with the high-voltage side is formed around the orbiting drive shaft of the orbiting scroll. Further, an annular groove 5d is provided on the pressure contact surface 7a of the bearing and the pressure contact surface 5e of the orbiting scroll on the back surface of the end plate 5a of the orbiting scroll.
Then, as shown in FIG. 3, the tip seal 8 is fitted in the groove to rotate the orbiting scroll under pressure. Here, the center of the annular groove is made to coincide with the center of the wrap of the orbiting scroll. Moreover, the cross-sectional shape of the groove is substantially U-shaped. On the other hand, the tip seal is formed in a substantially annular shape.
The outer circumference of the tip seal is pressed against the outer circumference of the groove. In addition, the cross-sectional shape of the tip seal,
It has a substantially trapezoidal shape. Furthermore, a gap is provided between the inner circumference of the tip seal and the inner circumference of the groove. A gap is provided between the inside of the tip seal and the bottom of the groove.

With the above construction, as shown in FIG. 2, the thrust force for pressing the orbiting scroll against the pressure contact surface 4c of the fixed scroll acts, while the center of the annular groove is aligned with the wrap of the orbiting scroll. Since it is aligned with the center, the thrust force and the compressive force act on the same line, and the pressures applied to both sides of the tip seal are almost equal, so that uneven wear can be prevented.

[0009]

As described above, in the present invention, the compression section and the electric motor are arranged vertically in the sealed container, and the compression section is
A spiral fixed scroll, an orbiting scroll that meshes with the fixed scroll to form a plurality of compression chambers, and a shaft that supports the orbital drive shaft of the orbiting scroll and forms a crankshaft at the upper end for orbital drive. A scroll compressor configured to include a bearing that pivotally supports the crankshaft, wherein a back pressure chamber is formed on the back surface of the orbiting scroll, and the orbiting scroll of the orbiting scroll of the bearing and the orbiting scroll is formed. An annular groove is provided on the back of the end plate,
A tip seal is fitted in the groove so that the orbiting scroll is pressed and rotated, and the center of the annular groove is made to coincide with the center of the wrap of the orbiting scroll. The cross-sectional shape of the groove is substantially U-shaped, while the tip seal is substantially annular, and
The outer circumference of the tip seal is pressed against the outer circumference of the groove portion, and the cross-sectional shape of the tip seal is
The trapezoid has a substantially trapezoidal shape, and a gap is provided between the inner periphery of the tip seal and the inner periphery of the groove, and a gap is provided between the inside of the tip seal and the bottom of the groove. Therefore, it is possible to prevent uneven wear of the tip seal for keeping the back pressure chamber on the back surface of the orbiting scroll at a low pressure, and as a result, it is possible to improve the performance and efficiency of the scroll compressor.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a scroll compressor showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part showing a stress state according to an embodiment of the present invention.

FIG. 3 is an enlarged sectional view of an essential part showing a tip seal fitting portion of the embodiment of FIG.

FIG. 4 is a vertical cross-sectional view of a scroll compressor showing an outline of a conventional example.

FIG. 5 is an enlarged sectional view of an essential part showing a state of stress applied to the orbiting scroll of the conventional example.

[Explanation of reference numerals] 1 sealed container 2 compression unit 3 electric motor 4 fixed scroll 4a fixed end plate 4b fixed scroll wrap 4c pressure contact surface 5 orbiting scroll 5a orbiting end plate 5b orbiting scroll wrap 5c orbiting drive shaft 5d groove 5e pressure contact surface 6 back pressure chamber 7 Bearing 7a Pressure contact surface 8 Tip seal 9 Compression chamber 10 Shaft 11 Crankshaft 20 High pressure part

Claims (8)

[Claims] 1. A compression unit and an electric motor are arranged vertically in a sealed container, and the compression unit includes a spiral scroll and a orbiting scroll that meshes with the fixed scroll to form a plurality of compression chambers. A scroll-type compressor comprising a shaft for supporting the orbiting drive shaft of the orbiting scroll and forming a crankshaft at the upper end for orbiting, and a bearing for axially supporting the crankshaft. A back pressure chamber is formed, and an annular groove is formed on the back surface of the end plate of the orbiting scroll on the pressure contact surface between the bearing and the orbiting scroll, and a tip seal is fitted into the groove to rotate the orbiting scroll under pressure. A scroll type compressor characterized by being made possible. 2. The scroll compressor according to claim 1, wherein the center of the annular groove is made to coincide with the center of the wrap of the orbiting scroll. 3. The scroll compressor according to claim 2, wherein the groove has a substantially U-shaped cross section. 4. The scroll compressor according to claim 2, wherein the tip seal has a substantially annular shape. 5. The scroll compressor according to claim 4, wherein the outer periphery of the tip seal is pressed against the outer periphery of the groove. 6. The scroll compressor according to claim 4, wherein the tip seal has a substantially trapezoidal cross-sectional shape. 7. The scroll compressor according to claim 4, wherein a gap is provided between the inner circumference of the tip seal and the inner circumference of the groove. 8. A gap is provided between the inside of the tip seal and the bottom of the groove.
The scroll compressor described.