JPH10213084A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a revolving scroll light in weight by being formed by a material with a coefficient of thermal expansion which is larger than that of a fixed scroll, suppress sealing leakage in a compression chamber and secure efficient compression. SOLUTION: This scroll compressor is constituted of a fixed scroll 25 having a spiral body 29 formed by an involute curve and a revolving scroll 17 having a spiral body 33 formed by the involute curve being engaged with the spiral body 29 of the fixed scroll 25 and forming a compression chamber. The revolving scroll 17 is formed by a material of a coefficient of thermal expansion which is larger than that of the fixed scroll 25, the base circle radius of the involute curve forming the external outer peripheral engagement surface 33a of the spiral body 33 of the revolving scroll 17 is made smaller than the base circle radius of the involute curve forming the external outer peripheral engagement surface 29a of the spiral body 29 of the fixed scroll 25, and the fixed scroll 25 and the revolving scroll 17 are surely engaged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor suitable for, for example, an air conditioner or a refrigerator.

[0002]

2. Description of the Related Art Generally, in a scroll compressor, as shown in FIG. 5, a fixed scroll 103 having a continuous spiral body 101 rising integrally from a substrate, meshes with a spiral body 101 of the fixed scroll 103, and a compression chamber 10 is formed.
5 is provided with a revolving scroll 109 which rises up integrally from the substrate, and the revolving scroll 109 is revolved with respect to the fixed scroll 103 so as to be centered from the outer peripheral ends of the revolving scrolls 101, 107. The refrigerant is compressed toward the discharge port 111 of the section.

[0003]

The compression chamber 105 of the scroll compressor is formed by the fixed scroll 103 and the spiral bodies 101 and 107 of the orbiting scroll 109 meshing with each other. It is formed of a lightweight metal having a different coefficient of thermal expansion. In particular, during operation, as shown in FIG. 6, the suction gas temperature shows a maximum temperature distribution at the central discharge port 111, and the orbiting scroll 109 receives strong thermal expansion. As a result, as shown in FIG. 7, the meshing state between the fixed scroll 103 and the orbiting scroll 109 is such that the sliding contact point between the orbiting scroll 109 and the fixed scroll 103 is only the outermost peripheral point 109a in the eccentric direction, and the other parts 10
In 9b-109f, there was a problem that a gap was generated and sealing leakage of the compression chamber 105 occurred, leading to a reduction in compression efficiency.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a scroll compressor which uses materials having different coefficients of thermal expansion, reduces seal leakage, and has a high compression efficiency.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention firstly provides a fixed scroll having a spiral body which rises integrally from a substrate and is formed by an involute curve, and a spiral of the fixed scroll. In a scroll compressor provided with a orbiting scroll in which a spiral formed by an involute curve forming a compression chamber that meshes with a body, the orbiting scroll is formed of a material having a larger coefficient of thermal expansion than a fixed scroll, The base circle radius of the involute curve forming the outer peripheral meshing surface of the spiral of the orbiting scroll is smaller than the base circle radius of the involute curve forming the inner inner meshing surface of the fixed scroll spiral.

Second, a fixed scroll having a spiral body which rises integrally from the substrate and is formed by an involute curve, and a spiral body formed by an involute curve which meshes with the fixed scroll to form a compression chamber are integrally formed from the substrate. In a scroll compressor having a rising orbiting scroll, the fixed scroll is formed of an iron-based material, and the orbiting scroll is formed of an aluminum-based alloy, while the involute curve that forms the inner inner circumferential meshing surface of the fixed scroll spiral is with respect to the base circle radius. The ratio of the base circle radius of the involute curve forming the outer peripheral meshing surface of the spiral body of the orbiting scroll to 0.9989 to 0.999.
Set to 5.

In a preferred embodiment, the base circle radius of the involute curve forming the inner inner circumferential meshing surface and the outer outer meshing surface of the fixed scroll, and the base circle of the involute curve forming the inner inner circumferential meshing surface of the orbiting scroll are described. Make the radii equal.

Alternatively, the base circle radius of the involute curve forming the inner inner meshing surface and the outer outer meshing surface of the orbiting scroll is made equal to the base circle radius of the involute curve forming the outer outer meshing surface of the fixed scroll.

According to such a scroll compressor,
As the orbiting scroll makes orbiting motion with respect to the fixed scroll, the refrigerant taken in from the outer peripheral end of each spiral body is sequentially compressed toward the central portion.

In this operation, the orbiting scroll made of an aluminum-based alloy is strongly affected by heat and greatly expands, compared to the fixed scroll made of cast iron. The involute curve ensures proper engagement with the fixed scroll. As a result, it is possible to obtain efficient compression in which the sealing leakage of the compression chamber is suppressed to a small level.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 2, reference numeral 1 denotes a sealed case having a suction pipe 3 and a discharge pipe 5, and a drive mechanism 7 serving as drive means is provided at a lower portion in the sealed case 1, and a compression mechanism serving as compression means is provided at an upper portion. Parts 9 are provided respectively.

The drive unit 7 has a rotor 13 fixed to the main shaft 11 and a stator 15 fixed to the case 1 side. When a current flows through the stator 15, the drive unit 7 rotates on the main shaft 11 via the rotor 13. Power will be given.

The main shaft 11 is eccentric e from the center axis X by a predetermined amount.
And a bearing portion 19 of the orbiting scroll 17 described later.
And an eccentric shaft portion 19 that engages with the main bearing member 21 fixed to the inner wall surface of the sealed case 1 at the upper end and a sub-bearing member fixed to the inner wall surface of the sealed case 1 at the lower end. 23
Are rotatably supported.

The compression mechanism 9 comprises a fixed scroll 25 and an orbiting scroll 17. The material of the fixed scroll 25 is cast iron, and the material of the orbiting scroll 17 is an aluminum alloy.

The fixed scroll 25 has a shape in which a spiral body 29 stands up integrally from a substrate 27. The spiral body 29 of the fixed scroll 25 is formed by an involute curve with the base circle center a. The outer side of the spiral body 29 is an outer outer peripheral meshing surface 29a, and the inner side is an inner inner peripheral meshing surface 29b.

The orbiting scroll 17 has a shape in which a spiral body 33 which forms a compression chamber 31 by meshing with a spiral body 29 of the fixed scroll 25 integrally rises from a substrate 35. The spiral body 33 of the orbiting scroll 17 has a base circle center a
Spiral body 3 formed by the involute curve
The outer side of 3 is an outer outer peripheral engagement surface 33a, and the inner side is an inner inner peripheral engagement surface 33b. The base circle radius of the outer peripheral involute curve of the orbiting scroll 17 is smaller than the base circle radius of the involute curve forming the inner inner peripheral meshing surface of the spiral body of the fixed scroll 25.

In this case, the spiral body 3 of the orbiting scroll 17
3 of the base circle of the involute curve radii a ₁ and a fixed base circle of the inner inner peripheral engaging surface 29b of the spiral body 29 of the scroll 25 radius a ₂ to form the outer periphery engaging surface 33a ratio a ₂ / a ₁ and efficiency of The relationship is from 0.9989 at which the base circle radius ratio a ₂ / a ₁ becomes the maximum efficiency from the experimental result of FIG.
It is desirable to set within the range of 0.995.

The radius of the base circle (dotted line in FIG. 1), which is the center of the base circle a of the involute curve forming the outer peripheral meshing surface 33a, is smaller than the involute curve forming the inner inner circumferential meshing surface 33b of the orbiting scroll 17. By setting as shown in FIG. 3, the inner inner peripheral meshing surface 33b of the orbiting scroll 17 can correctly mesh with the outer outer peripheral meshing surface 29a of the fixed scroll 25 without interference as shown in FIG.

On the other hand, the compression chamber 31 is
Of the spiral body 29 of the orbiting scroll 17 and the spiral body 33 of
By being shifted by 80 degrees, the spiral body 29 and the spiral body 33 are formed.

Further, the orbiting scroll 17 is provided with an orbiting motion without rotation of the rotating power from the eccentric shaft portion 19 of the main shaft 11 via the Oldham mechanism 37. As a result, the refrigerant introduced into the compression chamber 31 from the inlet cutout 39 is discharged from the discharge port 41 provided at the center of the fixed scroll 25 by the compression chamber 31 whose volume decreases from the outside toward the center. To move towards.

In FIG. 2, reference numeral 43 denotes an oil pump 4
Reference numeral 5 indicates an oil supply path for supplying the lubricating oil 47 to each sliding portion.

According to the scroll compressor configured as described above, as shown in FIG. 3, an assembling state is obtained in which the outer outer meshing surface 29a of the fixed scroll 25 and the inner inner meshing surface 33b of the orbiting scroll 17 are properly meshed. It does not impair the assemblability. Also, there is no seizure at the time of startup.

On the other hand, as the orbiting scroll 17 orbits with respect to the fixed scroll 25, the compression chamber 31
It moves from the outside to the center while reducing its volume, and discharges the compressed refrigerant from the discharge port 41. During this operation, the fixed scroll 25
In contrast, the orbiting scroll 17 undergoes a large thermal expansion, but a correct meshing state with the fixed scroll 25 is ensured by an involute curve that allows for the thermal expansion. As a result, the leakage of the seal in the compression chamber 31 is suppressed to be small, and efficient compression can be obtained.

[0025]

As described above, according to the scroll compressor of the present invention, the orbiting scroll that orbits can be made of a lightweight aluminum-based alloy, and the assemblability is not impaired. Moreover, burn-in at the time of startup can be prevented.

[0026] Even if it is affected by heat, the fixed scroll and the orbiting scroll are properly meshed with each other. As a result, the leakage of the seal in the compression chamber is suppressed to be small, and efficient compression can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a fixed scroll and an orbiting scroll of a scroll compressor according to the present invention;

FIG. 2 is a schematic cross-sectional view of the entire scroll compressor.

FIG. 3 is an explanatory diagram showing an engaged state of a fixed scroll and an orbiting scroll.

FIG. 4 is an explanatory diagram showing a relationship between displacement of an involute curve and efficiency.

FIG. 5 is an explanatory diagram showing a conventional fixed scroll and orbiting scroll meshing state.

FIG. 6 is an explanatory diagram of a distribution temperature of a discharge gas of a scroll compressor.

FIG. 7 is an explanatory diagram showing a meshing state during operation of a conventional fixed scroll and orbiting scroll.

[Explanation of symbols]

 17 Orbiting scroll 25 Fixed scroll 27 Substrate 29 Spiral body 29a Outer outer peripheral meshing surface 31 Compression chamber 33 Spiral body 33a Outer outer peripheral meshing surface a Base circle center

Claims (4)

[Claims] A fixed scroll having a spiral formed by an involute curve and a spiral formed by an involute curve forming a compression chamber which meshes with a scroll of the fixed scroll and rises integrally from the substrate. In a scroll compressor having an orbiting scroll that rises integrally, the orbiting scroll is formed of a material having a higher thermal expansion coefficient than a fixed scroll, while a base circle radius of an involute curve that forms an outer peripheral meshing surface of a spiral body of the orbiting scroll. A scroll compressor having a diameter smaller than a base circle radius of an involute curve forming an inner inner peripheral meshing surface of a fixed scroll scroll. 2. A base circle radius of an involute curve forming an inner inner meshing surface and an outer outer meshing surface of a fixed scroll is equal to a base circle radius of an involute curve forming an inner inner meshing surface of the orbiting scroll. The scroll compressor according to claim 1, wherein: 3. The method according to claim 1, wherein a base circle radius of an involute curve forming an inner inner circumferential meshing surface and an outer outer meshing surface of the orbiting scroll is made equal to a base circle radius of an involute curve forming an outer outer meshing surface of the fixed scroll. The scroll compressor according to claim 1, wherein: 4. A fixed scroll having a spiral body formed integrally with the substrate and formed by an involute curve, and a spiral body formed by an involute curve forming a compression chamber which meshes with the fixed scroll and integrally formed from the substrate. In a scroll compressor having an orbiting scroll, the fixed scroll is formed of an iron-based material and the orbiting scroll is formed of an aluminum-based alloy, while the orbiting scroll with respect to the base circle radius of the involute curve that forms the inner inner meshing surface of the fixed scroll scroll. A scroll compressor characterized in that the ratio of the base circle radius of the involute curve forming the outer peripheral meshing surface of the spiral body is set to 0.9989 to 0.9995.