JPH11324945A - Scroll type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the turning movement in balance while restraining the overturning phenomenon of a turning scroll by forming the whole of the back pressure chamber of a back surface of the turning scroll to the intermediate pressure, and forming a thrust receiver surface large at a bearing side. SOLUTION: This compressor is formed of a fixed scroll 4 fixed inside of a sealed container 1, a turning scroll 6 forming plural compression chambers with the fixed scroll 4, a shaft 10 for supporting a turning driving shaft 6c of the turning scroll 6 and formed with a clank shaft 8 at a lower end thereof for drive of turning, and for forming a lubricant feeding passage and a bearing 11 for pivotally supporting the clank shaft 8. In this case, a throttle mechanism 9a is provided in a lubricating oil feeding passage 9, and an annular groove 8a is provided in a bottom surface of the clank shaft 8 in a pressure-contact surface between the bearing 11 and the clank shaft 8, and a seal material 12 is fitted into the annular groove 8a so as to form a first back pressure chamber 11a at an intermediate pressure between a back surface of a turning driving shaft 6c and a central part of the bottom surface of the clank shaft 8, and a second back pressure chamber 13a at an intermediate pressure between a central part of the back surface of a turning end plate 6a and the peripheral part of the bottom surface of the clank shaft 8, and a third back pressure chamber 13b at an intermediate pressure between the periphery of the back surface of the turning end plate 6a and the bearing 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and more particularly, to a structure for widening a thrust receiving surface and suppressing a dance phenomenon of an orbiting scroll.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view of a conventional scroll compressor, and FIG.
This will be described with reference to FIG. The scroll compressor has an electric motor 2 and a compression unit 3 built in a sealed container 1, and the compression unit 3 includes a fixed scroll 4, an orbiting scroll 6, an Oldham ring 7 ', a crankshaft 8', an eccentric bearing 14, a bearing 11 ', It is mainly constituted by the shaft 10. In this configuration, a spiral fixed scroll wrap 4b is formed integrally with the fixed end plate 4a,
The fixed scroll 4 fixed to the 11 ', the orbiting scroll plate 6a integrally formed with the orbiting scroll plate 6a and the orbiting drive shaft 6c on the back surface are engaged with the orbiting scroll plate 6b. Are formed.

[0003] When the electric motor 2 rotates, the Oldham ring 7 is attached to the orbiting scroll 6 by the orbiting drive shaft 6c via an eccentric bearing 14 fitted on a crankshaft 8 'formed on the shaft 10 mounted on the bearing 11'. 'To make a turning motion while preventing rotation. The low-pressure refrigerant sucked into the compression section 3 from the suction pipe 15 by the orbiting motion of the orbiting scroll 6 is compressed while moving sequentially from the outer periphery to the center of the compression chamber 5 to become a high-pressure refrigerant, and is discharged from the discharge port 16 to the discharge chamber 17. The air is discharged from the discharge pipe 19 to the outside through the passage 18 and between the compressor 3 and the electric motor 2.

[0004] Also, a detaching force for pushing up the orbiting scroll 6 is acted on by the refrigerant pressure which has risen at the center of the compression chamber 5, and the fixed end plate 4a, the orbiting scroll wrap 6b and the orbiting end plate are turned.
In order to prevent a gap from being formed between the fixed scroll wrap 6a and the fixed scroll wrap 4b and causing a gas leak to lower the compression efficiency,
A high-pressure refrigerant is introduced between the center of the rear surface of 6a and the outer periphery of the bottom surface of the crankshaft 8 'to provide a high-pressure portion 20, and a high-pressure portion 21 is provided between the back surface of the swing drive shaft 6c and the center portion of the bottom surface of the crankshaft 8'. While providing
A low-pressure or intermediate-pressure back pressure chamber 13 'is provided on the outer periphery of the back surface, and a seal member 8a' for preventing leakage of the high-pressure refrigerant is provided on the pressure contact surface of the bearing 11 'in the middle thereof. , The airtightness of the compression chamber 5 is maintained against the separation force by the pushing force of the high-pressure refrigerant.

However, when the operation is started in a state where the refrigerant pressure on the suction side and the refrigerant pressure on the discharge side are almost equal, the pressure in the compression chamber 5 first increases, and then the pressure in the sealed container increases from the discharge chamber 17, so Out of balance.
At this time, the turning force transmitted from the crankshaft 8 'acting on the turning drive shaft 6c is divided into a force rotating orthogonally to a force pressing the orbiting scroll wrap 6b in the turning radius direction,
The point of reaction of the pressing force is the orbiting scroll wrap 6b constituting the compression chamber 5, and the point of action (upward arrow) and the point of reaction (downward arrow) are separated in the axial direction of the orbital drive shaft. It will act and cause a tilt.

[0006] For this reason, a dancing phenomenon occurs in the revolving head plate, and gas leakage occurs in the compression chamber to lower the compression efficiency.
There has been a problem that abnormal sliding occurs in each sliding portion, causing uneven wear of the sealing material. Further, the thrust force for suppressing the overturning phenomenon depends on the area of the high-pressure portion 20 to which a high-pressure load is applied.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and the entire back pressure chamber on the back surface of the orbiting scroll is set to an intermediate pressure, the thrust receiving surface on the bearing side is widened, and the orbiting scroll overturns. It is an object of the present invention to provide a scroll compressor capable of performing a well-balanced orbiting motion.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises an electric motor and a compression unit arranged vertically in a sealed container, and the compression unit is provided with a spiral wrap around a head plate. A orbiting scroll that meshes with the fixed scroll to form a plurality of compression chambers, and supports a orbital drive shaft of the orbiting scroll and forms a crankshaft at the lower end to orbitally drive the upper and lower ends. In a scroll compressor comprising a shaft having a lubricating oil passage extending therethrough and a bearing for supporting the crankshaft, a throttle mechanism is provided in the lubricating oil passage, and the bearing and the crankshaft An annular groove is provided on the bottom surface of the crankshaft of the pressure contact surface, a sealing material is fitted into the annular groove, and a first back pressure of an intermediate pressure is provided between the back surface of the turning drive shaft and a central portion of the crankshaft bottom surface. Forming a chamber A second back pressure chamber of intermediate pressure is formed between the center of the rear surface of the orbiting scroll head and the outer periphery of the bottom surface of the crankshaft, and an intermediate portion is provided between the outer peripheral portion of the back surface of the orbiting scroll head and the bearing. A third back pressure chamber for the pressure is formed.

Further, the center of the annular groove coincides with the center of the rotation axis of the orbiting scroll.

The cross-sectional shape of the annular groove is substantially U-shaped.

Further, the throttle mechanism is provided on the outlet side of the lubricating oil supply passage.

Further, the aperture mechanism is configured as a cylindrical hole.

Further, the outer periphery of the seal member is pressed against the outer periphery of the annular groove.

Further, the cross-sectional shape of the sealing material is substantially trapezoidal.

Further, a gap is provided between the inner periphery of the sealing material and the inner periphery of the annular groove.

[0016]

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view of a scroll compressor showing one embodiment of the present invention, FIG. 2 is an enlarged sectional view of a main part, and FIG. 3 is an enlarged sectional view of a main part showing a sealing material fitting portion. In the figure, an electric motor 2 and a compression unit 3 are arranged vertically in a sealed container 1, and the compression unit 3 is engaged with the fixed scroll 4 in a spiral shape to form a plurality of compression chambers 5 with each other. Orbiting scroll 6 to be formed and Oldham ring 7 for preventing rotation of the orbiting scroll 6
A shaft 10 having a lubricating oil passage 9 penetrating from an upper end to a lower end; The scroll compressor is constituted by the bearing 11 to be used.

In this configuration, the fixed scroll plate 4a is formed integrally with the fixed end plate 4a, and the fixed scroll 4 is pressed against the bearing 11, the swirl-shaped turning scroll wrap 6b is fixed to the turning end plate 6a, and the back surface. And a revolving scroll 6 integrally formed with a revolving drive shaft 6c and a revolving scroll wrap 6b
Are engaged with each other to form a plurality of compression chambers 5.

A throttle mechanism 9a having a hole diameter corresponding to a required supply amount of lubricating oil is provided at a lower outlet side of the lubricating oil supply passage 9, and a pressing contact surface between the bearing 11 and the crankshaft 8 has the same crankshaft. An annular groove 8a is provided on the bottom surface of 8, and a sealing material 12 is fitted in the annular groove 8a to shut off the pressure in the compression chamber 5 and the compressor.

A first back pressure chamber 11a for intermediate pressure is formed between the back surface of the orbiting drive shaft 6c and the center of the bottom surface of the crankshaft 8, and the center of the back surface of the orbiting end plate 6a of the orbiting scroll 6 is formed. A second back pressure chamber 13a of intermediate pressure is formed between the bottom surface of the crankshaft 8 and a third back pressure chamber 13b of intermediate pressure is formed between the outer peripheral portion of the back surface of the turning head plate 6a and the bearing 11. Although not shown in the direction of the solid line arrow in FIG. 2, a groove for flowing fluid is provided in the pressure contact surface 6 d of the turning head plate 6 a and the fixed head plate 4 a under the third back pressure chamber 13 b, and the entire back pressure chamber is maintained at an intermediate pressure. Configuration.

The center of the annular groove 8a coincides with the center of the rotation axis of the orbiting scroll 6. The annular groove 8a has a substantially U-shaped cross section. Further, the throttle mechanism 8a is a thin cylindrical hole, and an optimum oil amount is supplied to the compression chamber 5 by setting the inner diameter and length of the hole.

The outer periphery of the seal member 12 is pressed against the outer periphery of the annular groove. Further, the sealing material 12
Has a substantially trapezoidal cross section. Also,
A gap is provided between the inner periphery of the seal member 12 and the inner periphery of the annular groove.

With the above construction, the entire back pressure chamber on the back side of the orbiting scroll 6 is set to an intermediate pressure, the thrust receiving surface 11b on the bearing 11 side is widened, and the thrust force for pressing the orbiting scroll 6 against the bearing 11 is made uniform. Thus, the scroll compressor can suppress the overturning phenomenon of the orbiting scroll 6, perform a well-balanced orbiting motion, and improve performance and efficiency.

[0023]

As described above, in the present invention, the entire back pressure chamber on the back side of the orbiting scroll is set to the intermediate pressure, the thrust receiving surface on the bearing side is widened, and the thrust force for pressing the orbiting scroll against the bearing is made uniform. A scroll compressor that suppresses the overturning phenomenon of the orbiting scroll and achieves a well-balanced orbiting motion to improve performance and efficiency.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view of a main part showing an embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a main part showing a sealing material fitting portion of the embodiment of FIG. 2;

FIG. 4 is a longitudinal sectional view of a scroll compressor showing an outline of a conventional example.

FIG. 5 is an enlarged sectional view of a main part of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealed container 2 Electric motor 3 Compression part 4 Fixed scroll 4a Fixed end plate 4b Fixed scroll wrap 5 Compression chamber 6 Orbiting scroll 6a Orbiting head plate 6b Orbiting scroll wrap 6c Orbital drive shaft 6d Pressure contact surface 7 Oldham ring 8 Crank shaft 8a Annular groove 9 Lubricating oil Transmission path 9a Throttle mechanism 10 Shaft 11 Bearing 11a First back pressure chamber 11b Thrust receiving surface 12 Seal material 13a Second back pressure chamber 13b Third back pressure chamber

Claims (8)

[Claims] An electric motor and a compression section are arranged vertically in a sealed container, and the compression section is combined with the fixed scroll having a spiral wrap on a head plate to form a plurality of compression chambers. A orbiting scroll to be formed, a shaft that supports a orbiting drive shaft of the orbiting scroll, forms a crankshaft at the lower end, drives the orbital drive, and forms a lubricating oil passage that penetrates from the upper end to the lower end; A scroll compressor comprising: a throttling mechanism provided in the lubricating oil supply path; an annular groove provided in a bottom surface of the crankshaft in a pressure contact surface between the bearing and the crankshaft; A sealing material is fitted to form a first back pressure chamber for intermediate pressure between the rear surface of the orbiting drive shaft and the central portion of the crankshaft bottom surface, and a central rear surface of the orbiting scroll head plate and the crankshaft bottom. A second back pressure chamber of intermediate pressure is formed between the outer peripheral portions of the end plate, and a third back pressure chamber of intermediate pressure is formed between the outer peripheral portion of the back surface of the end plate of the orbiting scroll and the bearing. And scroll compressor. 2. The scroll compressor according to claim 1, wherein a center of said annular groove is made coincident with a center of a rotation axis of said orbiting scroll. 3. The scroll compressor according to claim 2, wherein the annular groove has a substantially U-shaped cross section. 4. The scroll compressor according to claim 1, wherein said throttle mechanism is provided on an outlet side of said lubricating oil supply passage. 5. The scroll compressor according to claim 1, wherein the throttle mechanism is a cylindrical hole. 6. The scroll compressor according to claim 1, wherein an outer periphery of said seal member is pressed against an outer periphery of said annular groove. 7. The scroll compressor according to claim 1, wherein the sealing member has a substantially trapezoidal cross section. 8. The scroll compressor according to claim 1, wherein a gap is provided between an inner periphery of the seal member and an inner periphery of the annular groove.