JPH08261182A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE: To improve compressing performance by effectively utilizing cooling air circulated in a cooling passage, so as to suppress a temperature rise of delivery fluid. CONSTITUTION: A receiver 16 having a flat space 18 in the inside is provided in a back surface side of a fixed scroll 14, to form a plurality of cooling air passage 19 of circulating cooling air between the receiver and the fixed scroll 14. A delivery piece 15 of connecting the flat space 18 to a compression chamber R1 and a delivery pipe part 20B of delivering compressed air to the outside from the flat space 18 are respectively provided in the receiver 16. In this way, compressed air or the like in a lap part 14C of the fixed scroll 14 and in each compression chamber R is cooled, also compressed air delivered from the delivery piece 15 can be simultaneously cooled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type fluid machine suitable for use in, for example, an air compressor or a vacuum pump.

[0002]

2. Description of the Related Art In general, a casing, a drive shaft whose tip side is rotatably provided in the casing, an orbiting scroll provided on the tip side of the drive shaft, and the orbiting scroll facing the orbiting scroll. And a fixed scroll that defines a plurality of compression chambers, a suction port that communicates with the compression chamber on the outer peripheral side among the compression chambers, and a fluid from the compression chamber that is provided at the center of the fixed scroll. An oil-free scroll-type fluid machine including a discharge port for discharging is known.

When this type of scroll type fluid machine is used as an air compressor, the orbiting scroll is orbited by rotating the drive shaft from the outside by an electric motor or the like, and the orbiting scroll is rotated between the orbiting scroll and the fixed scroll. While compressing the air sucked from the outside in the plurality of compression chambers formed in, the compressed air is discharged from the discharge port toward the external air tank or the like.

[0004]

By the way, in the above-mentioned conventional oil-free scroll type air compressor,
During the compression operation, compression heat is generated in each compression chamber, which causes thermal expansion and strain deformation due to non-uniform temperature in the wrap portion of the fixed scroll and the orbiting scroll, and the compressed air in the compression chamber becomes hot. There is a problem that the air expands and the compression efficiency decreases, and the air discharged from the discharge port cannot be efficiently stored in an air tank or the like.

In addition, in the refueling type scroll compressor described in JP-A-61-166991 (hereinafter referred to as other prior art), a refueling type scroll compressor is used as a refrigerating cycle refrigerant compressor. A structure has been proposed in which the refrigerant is used to cool the compression chamber between the fixed scroll and the orbiting scroll.

In this case, however, since the casing of the scroll type compressor itself constitutes the storage tank for the refrigerant, the entire structure becomes complicated and large, and it is possible to reduce the size and weight. There is a problem that you cannot do it.

The present invention has been made in view of the above-mentioned problems of the prior art. The present invention effectively utilizes the cooling air flowing through the cooling passage to effectively discharge the fluid discharged from the discharge port. It can be cooled, the compression performance can be greatly improved, the entire structure can be simplified, and the
An object of the present invention is to provide a scroll-type fluid machine that can be reduced in weight.

[0008]

In order to solve the above-mentioned problems, the present invention provides a casing, a drive shaft whose tip side is rotatably provided in the casing, and a drive shaft which is provided on the tip side of the drive shaft. An orbiting scroll, a fixed scroll that faces the orbiting scroll and defines a plurality of compression chambers between the orbiting scroll, a suction port that communicates with an outer peripheral compression chamber of the compression chambers, and the fixed The present invention is applied to a scroll type fluid machine including a discharge port provided at the center of a scroll for discharging a fluid from the compression chamber.

A feature of the structure adopted by the invention of claim 1 is that, on the back side of the fixed scroll, a fluid space for temporarily storing fluid discharged from the discharge port, the fluid space and the fluid space are provided. The purpose is to provide a cooling passage that is located between each compression chamber and that cools the fluid space and each compression chamber by circulating cooling air.

In this case, as in the invention described in claim 2, the fluid space is formed as a flat space so as to increase the contact area with the cooling air flowing in the cooling passage. It is preferable to have a structure.

Further, as in the invention described in claim 3,
On the back side of the fixed scroll, a passage portion is provided for returning a part of the fluid discharged from the discharge port into the fluid space into the compression chamber, and the cooling inside the cooling passage is provided around the passage portion. It may be configured to circulate the wind.

[0012]

With the above construction, in the invention described in claim 1,
The fluid discharged from the discharge port and temporarily stored in the fluid space can be cooled by the cooling air flowing through the cooling passage, and the cooling air at this time can also cool the fluid in each compression chamber. The temperature can be reliably reduced.

In this case, as in the second aspect of the present invention, the fluid space is formed as a flat space so as to increase the contact area with the cooling air flowing in the cooling passage. The heat dissipation of the fluid in the fluid space can be enhanced, and the fluid can be efficiently cooled.

According to the third aspect of the present invention, a passage portion is provided on the back surface side of the fixed scroll to circulate a part of the fluid in the fluid space into the compression chamber. It is possible to recirculate a part of the fluid cooled in step (4) into the compression chamber while cooling the fluid by the fluid wind even in the compression chamber side, and reliably suppress the temperature rise of the fluid.

[0015]

Embodiments of the present invention will be described below with reference to FIGS. Further, in the embodiment, an oilless scroll type air compressor will be described as an example of the scroll type fluid machine.

First, a first embodiment of the present invention will be described with reference to FIGS.

In the drawings, reference numeral 1 denotes a casing forming an outer frame of a scroll type air compressor.
Is a casing body 1A which is formed in a box shape from upper, lower, left and right side plates and a rear plate, and has a front side opening, and a cylindrical bearing portion 1B projectingly formed on the rear side of the casing body 1A.
And a flange portion 1C integrally formed on the front side of the casing body 1A. As shown in FIG. 2, a duct 24, which will be described later, is connected to the right side plate of the casing body 1A, and serves as a first vent hole for supplying cooling air from the duct 24 into the casing body 1A. The cooling air supply port 1D is formed, and the left side plate and the upper side plate of the casing body 1A have cooling air exhaust as second and third ventilation ports for exhausting the cooling air inside the casing body 1A to the outside. The mouths 1E and 1F are formed, respectively.

Reference numeral 2 designates a bearing 3 in a bearing portion 1B of the casing 1.
4 shows a drive shaft that is rotatably supported via 4, and the tip end side of the drive shaft 2 extends into the casing body 1A of the casing 1 to form a crank 2A, and the axis of the crank 2A is the axis of the drive shaft 2. It is eccentric to the axis by a certain dimension.
Further, the drive shaft 2 penetrates through a fan casing 21 described below from one end side of the bearing portion 1B and projects to the outside, and a centrifugal fan 22 and a pulley (not shown) described below are provided on the projecting end side. The drive shaft 2 is rotatably driven by an electric motor (neither is shown) via a belt on the pulley.

Reference numeral 5 denotes an orbiting scroll arranged in the casing body 1A of the casing 1 so as to face a fixed scroll 14 which will be described later. The orbiting scroll 5 is, as will be described later, a wrap portion on the surface side of the end plate 6A. 6B is provided upright, and the orbiting scroll main body 6 provided with heat radiating plates 6C, 6C, ... On the back side, and a disc-shaped plate-like body 7 attached to the back side of the orbiting scroll main body 6 are integrally formed. It is configured to The orbiting scroll 5 is rotatably attached to the crank 2A of the drive shaft 2 via an orbiting bearing 9 described later.

Reference numeral 6 denotes an orbiting scroll body. The orbiting scroll body 6 is provided with a disk-shaped end plate 6A and is erected on the surface of the end plate 6A. The center side of the end plate 6A serves as the winding start end and the outer peripheral side It is generally constituted by a spiral wrap portion 6B which is the end of winding. The wrap portion 6B of the orbiting scroll body 6 is disposed so as to overlap with a wrap portion 14C of the fixed scroll 14 described later while being offset by a predetermined angle.
A plurality of compression chambers R, R, ... Are formed between C and the wrap portion 6B of the orbiting scroll body 6.

When the drive shaft 2 is rotated by the electric motor and the orbiting scroll main body 6 (orbiting scroll 5) orbits, the compression chamber R on the outermost peripheral side, which is the lowest pressure side of each compression chamber R, will be described later. External air is sucked in through the suction port 14F of the fixed scroll 14, and the air is sequentially compressed in the compression chambers R while being sequentially compressed in the high-pressure compression chamber R located on the center side of the compression chambers R. The discharge port 1 of the fixed scroll 14, which will be described later, is fed from the compression chamber R2 on the highest pressure side.
It is discharged to an external air tank or the like (not shown) via 4G.

Further, a large number of heat radiating plates 6C, 6C, ... Are erected in parallel on the back side of the orbiting scroll body 6, and each of the heat radiating plates 6C transfers the compression heat generated during the compression operation in the casing body 1A. The first cooling air passages 6D, 6D are discharged into the flowing cooling air to efficiently cool the orbiting scroll body 6 and guide the cooling air from the cooling air supply port 1D of the casing 1 toward the cooling air exhaust port 1E. , ... are formed.

Reference numeral 7 denotes a plate-like body attached to the rear side of the orbiting scroll body 6 by a plurality of bolts 8 (only one is shown), and the plate-like body 7 has substantially the same diameter as the end plate 6A of the orbiting scroll body 6. A disk portion 7A formed in a disk shape of
A large-diameter boss portion 7B which is formed at the center of the back surface of the disk portion 7A and which is formed to project in the axial direction, and a plurality of small-diameter boss portions 7C which is formed to project at three locations on the outer peripheral side of the disk portion 7A (only one is shown. ) And is composed of. The large-diameter boss portion 7B supports the tip of the crank 2A of the drive shaft 2 via a swivel bearing 9 to be described later, and the small-diameter boss portions 7C to each auxiliary crank via a bearing 12 to be described later. 10
Is to support.

Reference numeral 9 denotes a slewing bearing inserted into the inner peripheral side of the large-diameter boss portion 8B of the plate-like body 7. The crank 2A of the drive shaft 2 is attached to the inner peripheral side of the slewing bearing 9, The orbiting bearing 9 rotatably supports the orbiting scroll 5 with respect to the crank 2A of the drive shaft 2.

Reference numeral 10 designates a plurality of auxiliary cranks (only one is shown) provided on the outer peripheral side of the back surface of the plate-like body 7. One end of each auxiliary crank 10 has a bearing 11 on the back plate of the casing body 1A. Is rotatably supported via
The other end is rotatably supported by each small-diameter boss portion 7C provided on the plate-shaped body 7 via a bearing 12. The auxiliary cranks 10 prevent the orbiting scroll 5 from rotating when the orbiting scroll 5 orbits. Reference numeral 13 indicates a balance weight fixed to the drive shaft 2, and the balance weight 13 serves to balance the rotation of the drive shaft 2.

Reference numeral 14 denotes a fixed scroll fixed to the flange portion 1C of the casing 1 via a bolt or the like (not shown). The fixed scroll 14 is a square plate-shaped end plate 14A and an outer edge side of the end plate 14A. Mounting flange portion 14B protruding from the end and abutting against the flange portion 1C
And a spiral wrap portion 14C that is erected on the surface of the end plate 14A, the center side of the end plate 14A is the winding start end, and the outer peripheral side is the end end of the winding, and a rear side of the end plate 14A shown in FIG. A large number of heat radiating plates 14 installed in parallel as shown in FIG.
D, 14D ... The projections 14E, 14E, ... (Refer to FIG. 5) having four screw holes are provided upright on the end plate 14A between the heat sinks 14D.

Here, on the upper side of the fixed scroll 14,
A suction port 14F communicating with the compression chamber R1 is bored, and the discharge port 14F is provided at the center of the end plate 14A of the fixed scroll 14.
G is provided, and one side opening of the discharge port 14G is opened to the compression chamber R2, and the other side opening is a discharge port 15 through a stepped cylindrical discharge piece 15 which will be described later. It is adapted to communicate with the flat space 18 of the body 16.

Reference numeral 16 denotes a flat container provided on the rear side of the end plate 14A of the fixed scroll 14, and the container 16
Is composed of an auxiliary frame body 17 described later and a lid body 20 described later that covers the auxiliary frame body 17, and compressed air discharged from the discharge port 14G is temporarily stored in a flat space 18 described later. It is like this.

Here, the auxiliary frame body 17 and the lid body 20 of the housing body 16 are fixed scroll 14 by a plurality of bolts 16C, 16C, ...
Is fixed to the back side of.

Reference numeral 17 denotes an auxiliary frame body forming a part of the housing body 16. The auxiliary frame body 17 has a bottom plate 17A formed in a substantially square shape as shown in FIG. Up,
It is integrally formed in a box shape with the lower side plate 17B, and forms a flat space 18 as a fluid space with the lid 20.
Then, the compressed air discharged into the flat space 18 widely contacts the cooling air in each cooling air passage 19 described later via the bottom plate 17A of the auxiliary frame body 17 and is cooled by this cooling air. It has become.

An insertion hole 17C into which the discharge piece 15 is fitted is formed in the center of the bottom plate 17A, and the large-diameter side opening of the discharge piece 15 opens into the flat space 18. ing. On the other hand, the auxiliary frame 17 has a side plate 17B.
Of the fixed scroll 14 located above the suction port 14F
The suction passage 17D is bored in the axial direction so as to correspond to.

Here, the bottom plate 17A of the auxiliary frame 17
Is in contact with the tip surface of each heat dissipation plate 14D of the fixed scroll 14 and forms a plurality of second cooling air passages 19 serving as cooling passages between the heat dissipation plates 14D. Then, one end of the duct 24 is connected to the right end of the cooling air passage 19 as shown in FIG. 2, so that the cooling air from the duct 24 can flow in each cooling air passage 19. The compressed air in the fixed scroll 14 and the flat space 18 can be efficiently cooled.

Reference numeral 20 denotes a lid body which covers the auxiliary frame body 17 and constitutes a part of the housing body 16. Above the lid body 20, an air intake port 20A communicating with the suction passage 17D of the auxiliary frame body 17 is provided.
And the air intake port 20A is provided with an intake port 14A from the outside.
Take in air to the F side. Further, the lid 20 has a flat space 1
A discharge pipe portion 20B communicating with the inside of the container 8 is provided so as to project to the outside, and the compressed air in the flat space 18 is stored in an external air tank or the like via the discharge pipe portion 20B.

Here, the compressed air contained in the flat space 18 of the container 16 is cooled by the cooling air flowing through the respective cooling air passages 19 on the back side of the bottom plate 17A, while the discharge pipe of the lid 20 is discharged. It is discharged from the portion 20B to the outside. Further, as shown in FIG. 3, a plurality of groove portions 20C are provided in parallel on the outer side surface of the lid body 20, and a plurality of heat dissipation plates 20D, 20D, ... Are formed between the groove portions 20C, and the flat space 18 The compressed air can be cooled efficiently.

Reference numeral 21 denotes a fan casing attached to one end side of the bearing portion 1B of the casing 1. The fan casing 21 is formed in a bottomed cylindrical shape, and the other side thereof is located on the outer peripheral side of the bearing portion 1B of the casing 1. Cooling air intake 21
A, 21A, ... Are formed in plural in the circumferential direction. Also,
A part of the outer peripheral side of the fan casing 21 communicates with a duct 24 described later, and a cooling air blowing port 21B for blowing cooling air from the fan casing 21 to the duct 24.
Are formed.

Reference numeral 22 denotes a centrifugal fan located inside the fan casing 21 and fixed to the outer peripheral side of the drive shaft 2 by a fixing member 23. The centrifugal fan 22 rotates together with the drive shaft 2 to cool the fan casing 21. External air is taken into the fan casing 21 from the wind inlet 21A as indicated by arrow A, and this air is used as cooling air from the cooling air blower port 21B through the duct 24 toward the casing body 1A side as indicated by arrow B. To do.

Reference numeral 24 denotes a duct for guiding the cooling air generated by the centrifugal fan 22 to the casing body 1A side.
One end side of the duct 24 is connected to the cooling air blowing port 21B of the fan casing 21, and the other end side is connected to the cooling air supplying port 1D of the casing body 1A and each cooling air passage 19.

As a result, the cooling air from the centrifugal fan 22 enters the cooling air passage 19 through the duct 24 as indicated by the arrow C.
As described above, the cooling air passages 19 are exhausted in the direction of arrow D in FIG. Further, this cooling air can also flow into each cooling air passage 6D and the like via the cooling air supply port 1D and the cooling air exhaust port 1E.

The scroll type air compressor according to this embodiment has the above-mentioned structure. Next, the compression operation of the scroll type air compressor will be described.

First, when the drive shaft 2 is rotated by the electric motor to orbit the orbiting scroll 5, the compression chambers R and R defined between the wrap portion 14C of the fixed scroll 14 and the wrap portion 6B of the orbiting scroll body 6 are formed. ,, continuously shrinks. As a result, the suction port 14F of the fixed scroll 14
While compressing the outside air sucked in from the compression chambers R sequentially, the compressed air is temporarily stored in the flat space 18 of the housing 16 from the discharge port 14G of the fixed scroll 14, and further from the flat space 18. The compressed air is delivered to the discharge pipe portion 20 of the lid body 20.
It is stored in an external air tank or the like via B.

Next, to explain the cooling action of the scroll type air compressor, when the drive shaft 2 is rotationally driven by the electric motor, the orbiting scroll 5 orbits to start the air compression operation and, at the same time, the centrifugal fan. 22 rotates. As a result, outside air is taken into the fan casing 21 from the cooling air intake port 18A of the fan casing 21 in the direction of the arrow A in FIG. 2, and this air is supplied as cooling air from the cooling air blowing port 21B of the fan casing 21. It flows out as shown by arrow B, is supplied into each cooling air passage 19 as shown by arrow C through the duct 24, and is discharged to the outside in the direction of arrow D.

At this time, the heat from each compression chamber R and the fixed scroll 14 which has become high temperature due to the compression heat is radiated to each cooling air passage 19 side through the radiator plate 14D, and at the same time, from the discharge piece 15. Since the compressed air is temporarily stored in the flat space 18, the heat of the compressed air can be efficiently dissipated to the cooling air passage 19 side through the bottom plate 17A of the auxiliary frame 17 in the cooling air passage 19 in the meantime. Thus, the cooling air flowing through can simultaneously convey these heats to the arrow D side.
Since the radiator 20D is provided on the lid 20 of the container 16, the compressed air in the flat space 18 can be cooled more effectively by this.

Thus, in this embodiment, the container 16 having the flat space 18 inside is provided with the bottom plate 17A and the side plates 17B.
The auxiliary frame body 17 is formed of a and a cover body 20 that covers the auxiliary frame body 17, and the housing body 16 is provided on the back surface side of the fixed scroll 14, thereby Each cooling air passage 19 is formed between them, and further, in the container 16, a discharge piece 15 that connects the flat space 18 and the compression chamber R1 and a discharge pipe that connects the flat space 18 to an external air tank or the like. Since the portion 20B is provided, the compressed air in the fixed scroll 14 and the compression chambers R can be cooled by the cooling air flowing in the cooling air passages 19, and the discharge piece 15 and the flat space 1 can be cooled.
The compressed air discharged into 8 can also be cooled at the same time.

Therefore, by circulating the cooling air in each cooling air passage 19, thermal expansion of the wrap portion 14C of the fixed scroll 14 and the wrap portion 6B of the orbiting scroll 5 due to the compression heat generated in each compression chamber R, etc. It is possible to effectively prevent distortion and deformation due to non-uniformity in temperature, prevent the temperature of the compressed air from the discharge pipe portion 20B from rising, and effectively improve the compression efficiency.

Further, the scroll air compressor can be constructed as an oil-free compressor, the overall structure can be simplified, the size and weight can be reduced, and the cooling performance can be improved. Has various effects.

Next, FIGS. 4 to 6 show a second embodiment of the present invention. In this embodiment, the same components as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. To do. However, the feature of this embodiment is that the end plate 14 of the fixed scroll 14 is
Two cylindrical protrusions 31, 31 are provided on the rear side of A, and the protruding end sides thereof are brought into contact with the rear side of the bottom plate 17A of the auxiliary frame body 17, and the protrusions 31 are provided with the housing 16 This is because the vent holes 32, 32 are provided as passage portions for communicating the flat space 18 with the compression chambers R.

Here, the protrusions 31 are opened in the intermediate compression chamber R3 in which the ventilation holes 32 are in an intermediate pressure state between the compression chamber R1 on the low pressure side and the compression chamber R2 on the high pressure side. As shown in FIG. 4, it is located between the wrap portions 14C of the fixed scroll 14 and is integrally formed on the rear side of the end plate 14A. Further, as shown in FIG. 6, each of the ventilation holes 32 is axially bored from the inner surface of the bottom plate 17A of the auxiliary frame body 17 toward each of the compression chambers R3 so as to penetrate through each of the protrusions 31, and has a flat shape. Part of the compressed air contained in the space 18
It is arranged so as to be guided into the compression chambers R3 in the direction of arrow E shown in FIG.

Thus, in this embodiment having the above-described structure, it is possible to obtain substantially the same effect as that of the first embodiment. However, particularly in this embodiment, the flat space 18 of the container 16 and the aforementioned Since each vent hole 32 is provided to communicate with each compression chamber R3, a part of the compressed air cooled in the flat space 18 is passed through each vent hole 32 in each compression chamber R3 in the arrow E direction. The high-temperature compression heat generated in each compression chamber R can be effectively cooled, and the orbiting scroll 5 and the fixed scroll 14 can be effectively returned.
It is possible to further improve the cooling efficiency of the above.

In the second embodiment, each ventilation hole 3
Although it has been described that two two are provided, the present invention is not limited to this, and any compression chamber R having an intermediate pressure between the compression chambers R1 and R2 and a passage portion communicating with the flat space 18 are provided. It may be possible to further provide a plurality of ventilation holes,
Thereby, the compression heat of each compression chamber R can be cooled more efficiently.

Further, in each of the above embodiments, the oilless scroll type air compressor has been described as an example, but the present invention is not limited to this, and an oilless scroll compression for compressing a gas other than air is used. It may be applied to a machine, and may be widely applied to a vacuum pump and the like.

[0051]

As described in detail above, according to the present invention, as described in claim 1, a fluid space for temporarily storing the fluid discharged from the discharge port on the back side of the fixed scroll,
Since it is arranged between the fluid space and each compression chamber, and a cooling passage is provided to cool the fluid space and each compression chamber by circulating cooling air, the cooling passage is generated in each compression chamber. The compression heat can be radiated to the cooling passage side, and at the same time, the fluid discharged from the discharge port can be radiated from the fluid space to the cooling air passage side.

As a result, by effectively utilizing the cooling air, it is possible to effectively prevent the thermal expansion or the like from occurring in the wrap portion of the fixed scroll or the orbiting scroll, and at the same time, store it in the fluid space from the discharge port. The fluid to be generated can also be cooled, and this fluid can be efficiently stored in an external tank or the like to reliably improve the compression performance.

Further, since the fluid from the discharge port is cooled, the casing itself is also used as a storage tank for the refrigerant like the scroll compressor described in other prior art, and the overall size is increased. It is possible to solve the problems such as the above, and to make the whole compact, so that the size and weight can be reduced.

Further, as in the invention described in claim 2,
By forming the fluid space as a flat space in order to increase the contact area with the cooling air flowing in the cooling passage, it is possible to further enhance the heat dissipation of the fluid in the fluid space. It is possible to reliably improve the cooling efficiency of the fluid.

Further, as in the third aspect of the present invention, by providing a passage portion on the back side of the fixed scroll for returning a part of the fluid in the fluid space into the compression chamber, Since a part of the fluid cooled in step (1) can be recirculated into the compression chamber, the fluid in the compression chamber can be positively cooled, and the compression efficiency of the fluid in the compression chamber can be further enhanced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a scroll type air compressor according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an enlarged partial cross-sectional view of a rear side of the fixed scroll shown in FIG. 1, a container, and the like.

FIG. 4 is a sectional view similar to FIG. 3, showing a scroll air compressor according to a second embodiment of the present invention.

5 is a sectional view taken along line VV in FIG.

6 is a sectional view taken along line VI-VI in FIG.

[Explanation of symbols]

 1 Casing 2 Drive shaft 2A Crank 5 Orbiting scroll 6A End plate 6B Wrap portion 6D First cooling air passage 14 Fixed scroll 14A End plate 14C Wrap portion 14F Suction port 14G Discharge port 16 Housing 18 Flat space (fluid space) 19 Second Cooling air passage (cooling passage) 32 Vent hole (passage part)

Claims (3)

[Claims] 1. A casing, a drive shaft whose tip side is rotatably provided in the casing, an orbiting scroll provided on the tip side of the drive shaft, and the orbiting scroll facing the orbiting scroll. A fixed scroll that defines a plurality of compression chambers in between, a suction port that communicates with the compression chamber on the outer peripheral side of each of the compression chambers, and a fluid provided from the compression chamber that is provided at the center of the fixed scroll. In a scroll-type fluid machine including a discharge port, a fluid space for temporarily storing a fluid discharged from the discharge port, a fluid space, and the compression chambers on the back side of the fixed scroll. A scroll-type fluid machine, characterized in that it is provided between the two and has a cooling passage for cooling the fluid space and each compression chamber by circulating cooling air. 2. The scroll type fluid machine according to claim 1, wherein the fluid space is formed as a flat space so as to increase a contact area with cooling air flowing in the cooling passage. 3. A passage portion is provided on the back surface side of the fixed scroll for returning a part of the fluid discharged from the discharge port into the fluid space into the compression chamber, and the cooling portion is provided around the passage portion. The scroll-type fluid machine according to claim 1 or 2, wherein the cooling air in the passage is circulated.