JPH0739835B2 - Scroll compressor - Google Patents

Description

The present invention relates to a scroll compressor.

[Conventional technology]

Regarding scroll compressors, various proposals for improvement have been published, including JP-A-50-32512. Conventionally, the orbiting scroll member, which started winding a spiral wrap from near the center, was orbited by a cantilevered crank. However, in this structure, the gas compressive force acting on the orbiting scroll member and the supporting force acting on the crank portion are separated from each other in the direction of the rotation axis, so that a lateral moment is generated on the axis, which causes mechanical loss and reliability. There was an unfavorable property in terms of surface. In order to improve this point, the shaft is passed through the center of the orbiting scroll member, the gas compressive force acting on the orbiting scroll member is supported by the crank portion provided on the same plane, and bearings are provided on both sides of the crank portion. The one without the moment of is proposed.

[Problems to be solved by the invention]

However, in the system with this shaft penetrating, since the shaft passes through the center of the orbiting scroll, the diameter of the winding start part of the scroll wrap is inevitably large due to the structure, and the winding start part departs from the center and rotates after the end of compression. The pressure on the inner surface and the outer surface of the orbiting scroll is different immediately before the inner surface of the scroll start end separates from the outer surface of the fixed scroll. However, there are some unfavorable points such as a decrease in adiabatic efficiency due to the re-expansion of gas from the compartment to the lower compartment and vibration noise due to a sudden pressure change.

An object of the present invention is to improve the adiabatic efficiency of a shaft-through type scroll compressor and reduce vibration noise.

[Means for solving problems]

In order to achieve the above object, a scroll compressor of the present invention includes a fixed scroll member having a wrap and an orbiting scroll member having a wrap, the orbiting scroll member having a wrap, the orbiting scroll member being a crank of the main shaft. In a scroll compressor that is swung so as not to rotate by the rotation section and the rotation preventing section, and the swiveling scroll wrap comes into contact with or comes close to the fixed scroll wrap to perform a compression action,
Orbiting scroll inner surface side compression start volume formed on the inner surface side of the winding end portion of the orbiting scroll member and the outer surface side of the fixed scroll member, and formed on the outer surface side of the winding end portion of the orbiting scroll member and the inner surface side of the fixed scroll member. Of the orbiting scroll outer surface side compression start volume, the volume immediately before the orbiting scroll inner surface side communication formed between the inner surface side of the winding start portion of the orbiting scroll member and the outer surface side of the fixed scroll member, and the winding start portion of the orbiting scroll member. The relationship between the outer surface side and the volume immediately before the orbiting scroll outer surface side communication formed between the inner surface side of the fixed scroll member is the ratio of the orbiting scroll inner surface side compression start volume to the orbiting scroll inner surface side immediately preceding communication volume, and the orbiting scroll outer surface. The orbiting scroll member is configured such that the ratio between the side compression start volume and the volume immediately before the orbiting scroll outer surface side communication is substantially equal. It is characterized in that the formation of the lap shape of the fixed scroll member.

[Action]

The points at which the inner surface of the winding end of the orbiting scroll and the outer surface of the winding end of the fixed scroll come into contact with each other and the gas compression action starts are called the orbiting scroll and the effective winding end of the fixed scroll, respectively. This volume is called the orbiting scroll inner surface side compression start volume. Note that the contact in this case includes a case where the contact is distant by several to several tens of microns due to the relationship between the leakage loss and the mechanical loss. Similarly, the points at which the outer surface of the winding end of the orbiting scroll and the inner surface of the winding end of the fixed scroll come into contact with each other to start the gas compression action are called effective winding end portions, and are called the compression start volume on the outer surface side of the orbiting scroll.

Then, the enclosed section reduces its volume while moving in the direction of the winding start portion of the scroll with the orbit of the orbiting scroll, compresses the gas, and increases the pressure of the gas.

This process progresses, and finally the inner surface of the winding start end of the orbiting scroll separates from the outer surface of the fixed scroll, but immediately before the separation, the volume of the partition surrounded by the inner surface side of the winding start portion of the orbiting scroll and the outer surface side of the fixed scroll. The volume of the partition enclosed by the outer surface of the orbiting scroll and the inner surface of the fixed scroll is referred to as the volume immediately before the outer surface of the orbiting scroll, and the pressure of each gas is immediately before or after the inner communication of the orbiting scroll. It is called pressure.

By making the ratio of the compression start volume of the orbiting scroll defined as above to the volume immediately before the communication of the orbiting scroll inner side and the ratio of the compression start volume of the orbiting scroll outer surface and the volume immediately before the communication of the orbiting scroll outer side almost equal, It is possible to equalize the gas pressures immediately before the communication inside and outside the scroll.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a vertical cross-sectional view of the scroll compressor 1.
2 is a cross section AA of FIG. 2 is an orbiting scroll wrap, 3 is an orbiting scroll member having an orbiting scroll wrap attached, 4 is a fixed scroll wrap, 5 is a fixed scroll member having a fixed scroll wrap attached, 6a, 6b
Is a main bearing provided on the fixed scroll member 5, 7 is a crank bearing provided on the orbiting scroll member 3, 8 is a main shaft, and 8a
Is a crank portion of the main shaft 8, 9 is an oil supply pump piece 8c attached to an oil supply hole 8b of the main shaft 8, an oil supply port for supplying oil from the oil supply hole 8b to the bearings 6a, 6b, 7; 10 is an oil drain hole; Suction port, 12 is a suction pipe, 13 is a pipe connecting piece, 14 is a motor composed of a stator 15 and a rotor 16, 17 is a mounting frame for mounting the fixed scroll member 5 on the stator 15, 1
8 is a discharge port, 19 is a discharge valve, 20 is a discharge pipe, 21 is a fixed scroll outer peripheral seal portion for preventing high pressure gas in the container 22 from leaking from the outer peripheral portion of the fixed scroll member 3, and 5a is a fixed scroll. An auxiliary rib for reinforcing the member and the mounting frame 17 is shown.

FIG. 3 is a side view showing the fixed scroll member 5 and the suction pipe 12 in a mounted state, and FIG. 4 is a sectional view B of FIG.
FIG. In these figures, 23 is a mounting spring for fixing the fixed scroll member 5, 24 is a mounting spring that also serves to mount the pipe connecting piece 13, and 25 is an O-ring for sealing.

FIG. 5 is a plan view of the orbiting scroll member 3, and the left half of FIG. 6 is a sectional view showing a state in which a fixed scroll member is combined in section C-C of FIG. 26 in these figures
Reference numeral a denotes a rotation preventing portion provided on the orbiting scroll member 3, and reference numeral 26b denotes a rotation preventing portion provided on the fixed scroll member 5. The right half of the sectional view of FIG. 6 shows an embodiment in which the rotation preventing portion sliding members 26c, 26d and the bearing sliding member 6c are inserted in order to improve the lubricating performance of the sliding portion. The rotation preventing portion 26a is a cylindrical pin having a radius R _P , and four pieces are provided on the outer peripheral portion of the orbiting scroll member 3 as shown in FIG.
The rotation preventing portion 26b provided on the orbiting scroll member 3 is
In order to allow the pin of the rotation prevention part 26a to slide in contact with the inner surface of the rotation prevention part 26a, a radius Rb is defined as a recess having a cylindrical surface whose radius is equal to the sum of the rotation radius Rc of the crank part 8a of the main shaft and the radius R _{P of the} pin.

FIG. 7 shows the orbiting scroll wrap 2 for showing the compression action.
And the fixed scroll wrap 4 is shown.

The operation of the embodiment will be described below with reference to these figures. When the motor 14 is energized, the rotor 16 rotates and the main shaft 8 fixed to this rotates. Then, the rotation prevention unit 26a,
Due to the action of 26b, the orbiting scroll member 3 makes an orbiting motion with a radius Rc by the crank portion 8a provided on the main shaft 8 without rotating on its own axis.

When the orbiting scroll member 3 orbits, the gas sucked into the outer peripheral portion of the fixed scroll member 5 via the suction pipe 12 and the suction port 11 becomes (A), (B), (C) in FIG.
The scroll wrap is compressed in the order of (D) and (A) from the winding end to the winding start.

The compression process will be described in detail with reference to FIG. (A) shows a state in which the orbiting scroll wrap 2 is positioned in the downward direction of the fixed scroll wrap 4, and the orbiting scroll wrap position is temporarily set as a reference position. In (A), the inner surface 2a of the effective winding end portion of one of the orbiting scrolls contacts the outer surface 4a of the effective winding end portion of the fixed scroll, and the orbiting scroll inner surface compression start volume V _I1
At the time of enclosing the gas, the winding end of the other orbiting scroll is open because the phase is 180 ° out of phase. The operation of one scroll is described below because it is complicated. At this time, since the inner surface 4a of the winding end portion of the fixed scroll facing the outer surface of the orbiting scroll is thinned so as not to contact the outer surface of the orbiting scroll, the outer surface side of the orbiting scroll is not closed yet and is compressed. Do not start.

The position where the orbiting scroll wrap 2 is rotated by θ = 90 ° is shown in (B). The inner volume of the orbiting scroll advances to the position of V _I2 . The outer surface of the wrap 2 of the orbiting scroll contacts the effective winding end portion 4b of the fixed scroll at a point of θ = θc before θ = 90 ° in this example, and the orbiting scroll outer surface compression start volume V _O1 (shown in the figure Enclose (omitted) and start compression. And in (B) of θ = 90 °, this section advances to the V _O2 position.

In this embodiment, the winding start portion 2c of the orbiting scroll is θ = 27.
Since it is in the 0 ° position, the orbiting scroll wrap 2 has θ = 9
After passing 0 °, the winding start portion 2c separates from the outer surface of the fixed scroll wrap. Therefore, the volume immediately before the communication on the inner surface side of the orbiting scroll corresponds to V _{I2 in} (B), and the volume immediately before the communication on the outer surface side corresponds to V _O2 . At this time, the gas pressure of each compartment is set to P _I2 , P _O2
Then, However, P _S : Gas pressure at the start of compression n: Polytropic index, Position of the effective winding end 4b of the fixed scroll so that
By setting = θc, P _I2 = P _O2 can be obtained.

By doing this, the winding start part of the orbiting scroll
At the moment when 2c is separated from the outer surface of the fixed scroll, the pressure on the inner and outer surfaces of the winding start part of the orbiting scroll is equal, so re-expansion from the outer surface to the inner surface and vibration noise due to sudden changes in pressure occur. It can be lost. In a conventional scroll compressor, the volume of the inner surface of the orbiting scroll is equal to that of the outer surface of the orbiting scroll when compressed, and the volume immediately before communication is about half the crescent-shaped length on the outer surface side of the orbiting scroll compared to the inner surface side. The gas pressure on the outer surface side was higher than that on the inner surface side. This resulted in various undesirable points when both compartments were achieved.

Further, the position of θ = 180 ° is shown in (C). (B) V _I2 and V
V ₃ mixed with _{O 2} decreases and moves to (D) where θ = 270 °.

In (D) and (A), the winding start end portion 4e between the inner surface side 4c and the outer surface side 4d of the winding start portion of the fixed scroll is configured to be slidable while being in contact with the winding start end portion 2e of the orbiting scroll. deep. The simplest shape that can be easily processed is, assuming that the orthographic scroll wrap thickness is T, the winding start end 2e of the orbiting scroll is a semicircle with a radius T / 2, and the winding start end of the fixed scroll is By making 4e a semicircle of radius (Rc + T / 2), the winding start end 2e of the orbiting scroll can be slid while inscribed in the winding start end 4e of the fixed scroll.

When θ = 360 °, it returns to (A) and V _{4 of} (D) becomes V _{5 of} (A). And the winding start end of the orbiting scroll
By sliding 2e while making contact with the winding start end 4e of the fixed scroll, the volume V _{5 of} this section is gradually reduced, and compressed gas is discharged from the discharge port 18,
At the position of (B) where θ = 450 °, V ₅ can approach zero. Further, by sliding while making contact with each other, it is possible to prevent the gas of V ₅ from flowing to V ₆ of the section (A) on the outer surface of the winding start portion of the orbiting scroll.
The entire V ₅ gas can be efficiently discharged to the discharge port 18.

The gas compressed as described above and discharged from the discharge port 18 is prevented from flowing backward to the fixed scroll wrap 3 by the discharge valve 19 shown in FIG. 2, and is discharged from the container 22 through the discharge pipe 20.

Regarding lubrication, oil is sucked from the hole in the center of the oil supply pump piece 9, and centrifugally applied to the main bearings 6a, 6b and the crank bearing 7 through the oil supply hole 8b and the oil supply port 8c for lubrication.

Further, the lubrication of the rotation prevention parts 26a, 26b is performed by the oil supply passage 27 having a large resistance communicating with the rotation prevention part 26b provided in the fixed scroll.
By providing the above, it is possible to supply an appropriate amount of oil to the sliding portion due to the pressure difference between the inside and outside of the fixed scroll member 5. It should be noted that as a means for further improving the reliability of the anti-rotation part, the anti-rotation parts 26c, 26 made of metal such as sintered alloy suitable for bearing
d can be inserted. When the rotation preventing portion 26d of sintered alloy having fine holes is inserted into the fixed scroll member 5, the oil that permeates through the sintered alloy can be efficiently lubricated with a small amount of oil.

In addition, in order to reduce the gas leakage from the minute gap between the orbiting scroll wrap 2 and the fixed scroll wrap 4, when only the supply to the rotation preventing portion 26 is insufficient, the lap oil supply passage 27 of FIG. 6 is provided. Is provided to inject a small amount of oil into the suction gas to improve efficiency.

In addition, the main bearings 6a, 6b and the crank bearing 7 have bearing metal 6c,
By inserting 6d and 7a, sufficient reliability can be obtained even when a plastic material is used for the fixed scroll member 5 and the orbiting scroll member 3.

Next, the function of the mounting springs 23 and 24 shown in FIGS. 3 and 4 will be described. Especially when a large amount of liquid refrigerant is sucked from the suction pipe 12 at the time of starting the compressor and the pressure in the fixed scroll wrap 4 becomes abnormally high in the middle of the compression stroke, the mounting springs 23 and 24 have appropriate elasticity. By having
These are elastically deformed, a minute gap is opened between the upper and lower fixed scroll members 5 to leak the gas under compression, the abnormal pressure is reduced, and the fixed scroll member 5 or the wrap 4 is prevented from being destroyed. You can

In the above embodiments, a structure is provided in which a clearance is provided on the inner surface side of the winding end portion of the fixed scroll wrap in order to adjust the volume at the start of compression, and the position of the effective winding end portion 4b is shifted, but other Alternatively, a structure may be provided in which a relief is provided on the outer surface side of the winding end portion of the orbiting scroll.

Next, as a structure for reducing the rotational vibration, consider the structure shown in FIG. 8 in which the wraps 2 provided on both sides of the orbiting scroll member 3 are displaced by 90 ° in the rotational direction, and the fixed scroll wrap 4 is also displaced by 90 ° correspondingly. You can By thus shifting the wraps by 90 ° between the upper and lower surfaces, it is possible to provide a scroll compressor with low vibration in which the rotational vibration is reduced to about half.

Further, as shown in FIG. 2, the fixed scroll member 5 rotation preventing portion 26b, the bearing 6a and the mounting frame 17, the orbiting scroll member 3, the rotation preventing portion 26a and the crank bearing 7 are integrally formed by using, for example, plastic, Accumulation of dimensional tolerances during assembly can be reduced, and a scroll compressor with higher accuracy and efficiency can be obtained.

〔The invention's effect〕

According to the present invention, it is possible to equalize the gas pressures on the inner surface side and the outer surface side of the winding start portion of the orbiting scroll immediately before the winding start end portion 2e of the orbiting scroll leaves the outer surface 4d of the winding end portion of the fixed scroll. It is possible to obtain the effects of improving the heat insulation efficiency and reducing vibration noise.

[Brief description of drawings]

FIG. 1 is an embodiment of the present invention and is a sectional view taken along the line AA of FIG.
2 is a sectional view of a scroll compressor according to an embodiment of the present invention, FIG. 3 is a side view of the fixed scroll member of FIG. 1, FIG. 4 is a plan view of FIG. 2, and FIG. FIG. 6 is a plan view of the member, FIG. 6 is an assembled cross-sectional view taken along the line CC of FIG. 5, FIG. 7 is an explanatory view of the compression action, and FIG. 8 shows a fixed scroll member and an orbiting scroll member of another embodiment. FIG. 2 ... Orbiting scroll wrap, 2c ... Orbiting scroll winding start portion, 3 ... Orbiting scroll member, 4 ... Fixed scroll wrap, 4d ... Fixed scroll winding beginning portion outer surface,
5 ... Fixed scroll member, 6a, 6b ... Bearing, 7 ... Crank bearing, 8 ... Main shaft.

Claims (2)

[Claims] 1. A fixed scroll member having a wrap, and an orbiting scroll member having a wrap and penetrating a main shaft, the orbiting scroll member orbiting so as not to rotate by a crank portion and a rotation preventing portion of the main shaft. In the scroll compressor for performing the compression action by bringing the orbiting scroll wrap into contact with or close to the fixed scroll wrap, the orbiting scroll inner surface formed by the inner surface side of the winding end portion of the orbiting scroll member and the outer surface side of the fixed scroll member. The side compression start volume, the orbiting scroll outer side compression start volume formed by the outer surface side of the winding end portion of the orbiting scroll member and the inner surface side of the fixed scroll member, and the inner surface side of the winding start portion of the orbiting scroll member and the fixed scroll. Orbiting scroll formed on the outer surface side of the member, the volume immediately before communication with the inner surface side, and the orbiting scroll The relationship between the outer surface side of the winding start portion of the material and the volume immediately before the orbiting scroll outer surface side communication formed between the inner surface side of the fixed scroll member is the ratio of the orbiting scroll inner surface side compression start volume and the orbiting scroll inner surface side immediately before communication volume. And a wrap shape of the orbiting scroll member and the fixed scroll member is formed such that the ratio of the volume of the orbiting scroll outer surface side compression and the volume immediately before the orbiting scroll outer surface side communication is substantially equal. . 2. The wrap thickness of the orbiting scroll member is T,
When the orbiting radius is Rc, the tip of the winding start portion of the wrap of the orbiting scroll member is a semi-circle of radius T / 2, and the winding start end of the wrap of the fixed scroll member is radius (Rc + T / 2)
The scroll compressor according to claim 1, wherein the scroll compressor is a semi-circular arc.