JPH11141301A - Twin scroll type fluid machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a twin scroll type fluid machinery which can attain improvement in suction efficiency and high compression while miniaturizing a device on its suction side. SOLUTION: This fluid machinery is composed of a turning scroll having a spiral groove and a spiral lap on its both surfaces, and a fixed scroll having a spiral groove and a spiral lap to be fitted to the lap on the turning scroll. In such a case, a peripheral wall 20a of the spiral groove of one scroll is semi- circularly formed on its side of the center of the scroll. An exhaust port is formed on the semi-circular surface, on the inner wall side of the spiral groove. A discharge port 7 is formed on the bottom side of the peripheral wall of the center side of the scroll, while being communicated with the exhaust port through an induction passage 31. An inner peripheral end of the lap of the other scroll is slid against the peripheral wall of the center of one scroll. Compressed fluid can be discharged from the discharge port.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a compressor, an expander,
The present invention relates to a twin scroll fluid machine functioning as a vacuum pump, and in particular, comprises one orbiting scroll having spiral wraps formed at least on both axial sides, and a plurality of fixed scrolls having spiral wraps fitted to the wraps, The present invention relates to a twin scroll fluid machine configured to be able to revolve without rotating the orbiting scroll.

[0002]

2. Description of the Related Art Conventionally, a first scroll is formed in a casing surrounded by a peripheral wall, and a suction scroll and a discharge port are provided in a peripheral wall and a central area thereof, respectively. A revolving scroll having a second wrap that can be fitted, for example, by revolving the revolving scroll without rotating, so that gas introduced into the casing from the suction port is interposed between the first and second wraps. A scroll fluid configured to be able to move toward the center and compress while gradually reducing its volume with the revolving motion of the orbiting scroll while taking in the closed space formed in the orifice, and discharge the high-pressure air to the outside from the discharge port. Machines are known.

Such a scroll fluid machine is a so-called face-to-face scroll fluid machine in which one fixed scroll wrap and one orbiting scroll wrap are fitted to each other to perform expansion, compression or pressure-feeding motion (for example, see Japanese Patent Application Laid-Open (JP-A) no. JP-A-50-32512), and a pair of fixed scrolls each having a wrap that can be fitted with the wrap are sandwiched on both sides of one orbiting scroll having wraps formed on both sides in the axial direction. A so-called twin scroll fluid machine (Japanese Patent Publication No. Sho 63-42081) has been proposed in which a predetermined expansion, compression or pressure-feeding motion is performed on both sides by the revolving motion of the scroll.

[0004]

However, in any of the above-mentioned scroll fluid machines, the wraps of both scrolls have substantially the same number of turns and are 180 degrees apart from each other.
The following problems occur on both the suction side and the discharge side because the fitting is performed out of phase. That is, on the suction side, the wrap start ends located on the outer peripheral side of the scroll come into contact with the other wrap side wall surfaces at a position shifted by 180 ° in phase, and each wrap start end position is set at each wrap start position in order to adopt a configuration that forms a compression chamber. Provide a suction port or 1
It is necessary to provide a semicircular detour communicating with one suction port provided at a position separated by 80 ° on the outer peripheral side of the wrap,
As a result, the size of the apparatus is increased and the number of processing steps is increased.

[0005] Providing a plurality of suction ports as described above means that a plurality of compression chambers perform a compression process in parallel with a phase shift of 180 °, so that so-called high compression becomes difficult, and The intake volume into the closed space sandwiched between the wraps is reduced accordingly, and the suction efficiency cannot be improved.

On the other hand, also on the discharge side, since a bearing portion for inserting a rotary shaft and others is located at the center of the scroll,
The end of the wrap and the discharge port must be provided at an intermediate position of the involute curve on the outer peripheral side of the bearing, and in this state, arranging the start of each wrap 180 ° out of phase results in the final compression chamber The compression ratio is reduced because it is opened to the discharge port while the volume is large. However, a large capacity of the final compression chamber leads to a long sealing line, resulting in a reduction in sealing performance and a tendency for backflow to occur, leading to a reduction in compression efficiency.

In order to solve such a drawback, a so-called face-to-face scroll fluid machine is configured such that the main shaft of the orbiting scroll is provided on the back side of the wrap and one discharge port is provided at the center of the fixed scroll. In the scroll fluid machine, as shown in the embodiment described below,
Since the orbiting scroll is disposed so as to be sandwiched between the pair of fixed scrolls, the main shaft must be disposed so as to penetrate the center of the fixed scroll. Inevitably manifests itself.

SUMMARY OF THE INVENTION In view of the drawbacks of the prior art, it is an object of the present invention to provide a twin scroll fluid machine capable of achieving a high suction efficiency and a high compression while reducing the size of the device on the suction side. It is another object of the present invention to provide a twin scroll fluid machine capable of improving discharge efficiency and achieving high compression. It is another object of the present invention to provide a twin scroll fluid machine that improves the sealing performance between wraps and improves the compression efficiency.

[0009]

According to the present invention, there is provided an orbiting scroll having spiral grooves and spiral wraps formed on both sides of an end plate;
In a twin scroll fluid machine, comprising a fixed scroll having a spiral groove and a spiral wrap fitted to the spiral wrap, and capable of revolving without rotating the orbiting scroll, the spiral of one side scroll The scroll center-side peripheral wall surface of the groove is formed in a semicircular surface, and a discharge port is provided on the inner wall side of the spiral groove of the semicircular surface, and the discharge hole is provided on the back side of the scroll center-side peripheral wall surface. A discharge port is formed from the outlet through a conduction path, and the inner peripheral end of the other scroll that fits into the spiral wrap slides along the peripheral wall of the scroll center, and discharges the compressed fluid from the discharge port. It is characterized by being configured to be possible.

According to the present invention, the peripheral wall of the spiral groove of the one-sided scroll is formed in a semicircular surface, and a discharge port is provided on the inner wall side of the spiral groove of the semicircular surface. Since the inner peripheral end of the wrap of the other scroll fitted to the helical wrap is slidably contacted along the peripheral wall surface of the scroll center, and the compressed fluid can be discharged from the discharge port, the helical groove bottom surface is formed. Thus, the compressed fluid can be further compressed as compared with the case where the discharge port is provided, so that compression efficiency can be improved and high compression can be achieved.

That is, by providing a discharge port on the inner wall side of the helical groove of the semicircular surface, the volume of the final compression chamber can be reduced, thereby improving the discharge efficiency and increasing the compression ratio. You can do it. It is desirable that the discharge port is formed inside the center line of the spiral groove. In this case, the volume of the final compression chamber can be further reduced, and the discharge efficiency is improved and the compression ratio is further increased. Can be higher.

[0012] Further, the scroll center side peripheral wall surface in contact with the wrap inner peripheral end on the discharge side is formed in a semicircular shape, and the wrap inner peripheral end is disposed so as to slide along the scroll central side peripheral wall surface. In this case, the sealing performance is improved at the inner peripheral end.In this case, without directly facing the inner peripheral end of the wrap and the discharge port, the discharge port is formed through the conduction path on the deep side of the scroll center side peripheral wall surface. , And the effect is further enhanced.

It is preferable that the radius of the semicircular shape of the peripheral wall on the center side of the scroll is set to be substantially equal to the eccentricity of the orbiting scroll and the fixed scroll, in other words, substantially equal to the orbiting radius. Further, as described above, the reduction in the volume of the final compression chamber also shortens the seal line, which results in an improvement in sealing performance and prevention of backflow, and an improvement in compression efficiency.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, unless otherwise specified. It is only an example.

FIG. 3 shows a twin-type scroll compressor to which the present invention is applied. One orbiting scroll 1 which is supported on a central crank portion of a main shaft 6 and has orbital wraps formed on both axial sides, respectively. A pair of fixed scrolls 2A and 2B forming a fixed wrap to be fitted, and three eccentric rotation shafts 3 for rotation control provided on the outer peripheral side of the scroll by 120 ° in the circumferential direction, respectively. It is configured.

The fixed scrolls 2A and 2B are in the shape of a circular cap, and their peripheral walls functioning as a casing are brought into contact with each other via a sealing member to form a closed space therein, and the center hole 4 is provided with a bearing 5 via a bearing 5. And the main shaft 6 is rotatably supported by two-point support. As described later, spiral fixed wraps 10 are arranged symmetrically around the bearing 5 so as to face each other, and a discharge port 7 is provided at a central area side and an outer peripheral edge of one fixed scroll 2A. The suction port 8 is formed.

On the other hand, the orbiting scroll 1 is formed with orbiting wraps on both sides in the axial direction as described above, and is configured to be able to be fitted to the fixed wrap 10 and to support the eccentric rotary shaft 3 on the peripheral side thereof. . Then, both support shafts of the eccentric rotary shaft 3 are supported by the fixed scrolls 2A and 2B, and the rotation of the orbiting scroll 1 is restricted by two-point support.

Since such a configuration is publicly known, a detailed description thereof will be omitted. In the twin type scroll compressor, the main shaft 6 is provided at the center of the pair of fixed scrolls 2A and 2B.
In other words, since the bearing 5 must be provided, and in other words, the discharge port 7 must be provided off the center, there is a problem that miniaturization and high compression are difficult.

Therefore, in order to solve the above-mentioned disadvantage, the present embodiment can adopt a wrap shape as shown in FIG. For example, in FIG. 2, reference numeral 10 denotes a wrap formed on the fixed scroll 2 side, and a main shaft 6 provided at a central portion.
(Fig. 3) Around the center hole 4 through which the bearing 5 formed in an involute shape is spirally approximately 5.5π from the bearing 5 portion.
(2.75 turns), and the scroll groove 20 sandwiched between the wrap start end 10a and the wall surface of the bearing 5
The peripheral wall on the starting end side, that is, the peripheral wall on the scroll center side is formed in a semicircular shape, and the discharge port 7 is perforated in the semicircular surface 20a.

In this case, the shape of the peripheral wall surface on the scroll center side is set such that its radius is substantially equal to the amount of eccentricity x between the orbiting scroll shaft 1a and the fixed scroll shaft 2a, in other words, the turning radius. On the other hand, the wrap 15 on the orbiting scroll 1 side
The spiral is extended 180 ° inward on the inner peripheral side with respect to the wrap 10 on the fixed scroll side, and its starting end 15a is brought close to the semicircular surface 20a on the scroll groove starting end 10a side or in response to the turning motion. In addition to being configured to be slidable, the tip is cut into a semicircular shape to facilitate the slidable contact.

As a result, when the orbiting scroll 1 is turned around the fixed scroll shaft 1a, the wrap end on the orbiting scroll side, that is, the wrap inner peripheral end 15a
However, the sliding contact is made along the semicircular surface 20a, and a smooth sliding contact movement becomes possible.

Conversely, because of the above configuration, it can be said that the inner peripheral end 15a of the wrap can be extended 180 ° to the discharge port 7, whereby the wrap inner peripheral end 15a
The closed space 30 can be maintained until the pressure reaches the inlet end of the discharge port 7, and the volume ratio is 24 in comparison with the conventional scroll compressor in which the final compression chamber is opened 180 ° before the discharge port 7. % And the seal length can be reduced by as much as 33%, and the compression efficiency is improved accordingly.

In the embodiment, since the discharge port 7 is formed in the spiral groove in front of the semicircular surface 20a, the inner peripheral end 15a of the wrap reaches the inlet end of the discharge port 7. At this point, more specifically, before the wrap inner peripheral end 15a reaches the semicircular surface 20a, there is a problem that the final compression chamber 30 is opened.

Therefore, in FIG.
In addition to piercing the discharge port 7 in the bearing 5 portion on the back side of 0a,
A discharge port 20b is provided on the inner wall side of the spiral groove inside the center line of the spiral groove on the semicircular surface 20a, and a conduction path 31 that connects the discharge port 20b and the discharge port 7 is formed in the bearing 5. doing.

According to this configuration, the wrap inner peripheral end 15a
Since the final compression chamber 30 is not opened until it comes close to the inner wall side of the spiral groove of the bearing 5, the volume ratio is 11% and the seal length is 24% as compared with the above embodiment. It was confirmed that the compression chamber could be reduced and the compression efficiency was further improved.

In the present embodiment, the wrap outer peripheral end 15b side of the orbiting scroll also extends the 180 ° spiral, and when the wrap outer peripheral end 10b coincides with the fixed scroll wrap outer peripheral end 10b, the first wrap closed space is formed. Suction space 3
3 can be increased, and one inlet 8 (Fig. 3)
May be provided in the area where the wraps 10a / 15a coincide with each other on the fixed scroll 2 side, whereby the operation of the embodiment can be smoothly achieved.

Although the present embodiment has described the operation and configuration of the scroll compressor, the present embodiment is not limited to this, and can be applied to an expander and a pump.

[0028]

According to the present invention, as described above, the discharge port is provided on the inner wall side of the spiral groove on the scroll center side peripheral wall surface of the spiral groove of the one-side scroll, so that the volume of the final compression chamber is increased. Can be reduced, the discharge efficiency can be improved and the compression ratio can be increased accordingly, and the compression efficiency can be improved and the compression can be increased.

The scroll center side peripheral wall that is in contact with the inner peripheral end of the wrap on the discharge side is formed in a semicircular shape, and the inner peripheral end of the wrap is disposed so as to slide along the scroll central side peripheral wall. The sealing performance is improved at the inner peripheral end. And so on.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a wrap shape and an arrangement thereof according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a wrap shape and an arrangement state thereof according to a comparative example.

FIG. 3 is an overall sectional view of a twin-type scroll compressor to which the present invention is applied.

[Explanation of symbols]

 7 Discharge port 15a Wrap inner peripheral end 20a Scroll center side peripheral wall surface 20b Discharge port 31 Conductive path

Claims (2)

[Claims] An orbiting scroll having a spiral groove and a spiral wrap formed on both sides of an end plate; and a fixed scroll having a spiral groove and a spiral wrap fitted to the spiral wrap. In the twin-type scroll fluid machine configured to be able to revolve without rotating the scroll, a spiral center side peripheral wall surface of the spiral groove of the one-sided scroll is formed in a semicircular surface, and the spiral of the semicircular surface is formed. A discharge port is provided on the inner wall side of the groove, and a discharge port is formed through the conduction path from the discharge port on the back side of the peripheral wall surface on the center side of the scroll, and the other scroll is fitted with the spiral wrap. A twin scroll fluid machine, wherein an inner peripheral end of the wrap slides along the peripheral wall surface on the scroll center side so that compressed fluid can be discharged from the discharge port. 2. The twin scroll fluid machine according to claim 1, wherein the discharge port is formed inside a center line of the spiral groove.