JP2002235680A - Scroll type compressor for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll type compressor for a fuel cell allowing significantly reducing noises such as a whizzing sound when rotating a rotation balancer. SOLUTION: This scroll type compressor 100 is formed by a drive motor 130, a drive crankshaft 131, a fixing scroll 110, a turning scroll 120 and the rotation balancer W mounted for reducing unbalance originating from a turning movement of the turning scroll. The rotation balancer is approximately fan- shaped and at least a part of its front end face abutting on surrounding gas at rotating is formed in a smooth curved surface. Since at least the part of the front end face is formed by the smooth curved surface, air flow generated when rotating the rotation balancer becomes smooth for reducing generation of the whizzing sound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type compression engine for a fuel cell having a rotary balancer capable of reducing noise during compressor operation.

[0002]

2. Description of the Related Art Scroll type compressors, which are a type of compressor, are widely used in home air conditioners, air conditioners for automobiles, etc. because of their small size and high efficiency. Development of a scroll compressor for fuel cells used to supply compressed gas (hydrogen, oxygen or air, etc.) to the electrodes of fuel cells (hydrogen-oxygen type)
Research is currently being actively conducted. The basic structure of a scroll compressor is such that a fixed scroll fixed to a housing or the like is engaged with a orbiting scroll driven by a drive motor or the like to perform a revolving motion, and a compression chamber formed between the fixed scroll and the orbiting scroll. Is compressed and discharged by the orbiting motion of the orbiting scroll. Here, since the orbiting scroll orbits (revolves) at a position eccentric from the axis of the drive shaft, a centrifugal force corresponding to the eccentricity acts on the orbiting scroll. In order to eliminate this imbalance, usually, a rotation balancer is provided on the side opposite to the eccentric side. The weight and shape of the rotary balancer are determined in consideration of not only static balance but also the above-described dynamic balance based on the moment of inertia. In this way, vibration can be reduced and critical speed can be improved, and both miniaturization and high speed can be achieved.

[0003]

However, the scroll compressor for a fuel cell has the same basic structure as that of the conventional scroll compressor, but the structure of the details differs according to the use conditions. There are new problems that do not exist in the scroll compressor, and conversely, they may not have the conventional problems that exist in the conventional scroll compressor. For example, in the case of a conventional scroll compressor, lubrication of a bearing portion and the like is performed by forced lubrication using a lubricating oil. For this reason, the rotating balancer is often in a state of being immersed in the lubricating oil. If the rotating balancer rotates in such a state, stirring resistance occurs in the rotating balancer, which is a major factor in power loss. Such a problem is disclosed in Japanese Patent Laid-Open No. 4-2
It is pointed out in Japanese Patent Application Laid-Open No. 65485, Japanese Patent Application Laid-Open No. 62-271984, Japanese Patent Application Laid-Open No. 61-118579, or the like.

On the other hand, in the case of a scroll compressor for a fuel cell, the object to be compressed is a gas such as air or hydrogen, and a refrigerant (gas) that can be mixed with lubricating oil as in a conventional scroll compressor. different. In the case of a scroll compressor for a fuel cell that supplies a compressed gas to the electrode of the fuel cell, even if a small amount of lubricating oil or the like is mixed in the compressed gas, the electrode may be damaged. The grease-enclosed bearings and the like are used for the bearings and the like in the scroll-type compressor, and are not lubricated by lubricating oil. Since lubricating oil (incompressible fluid) does not exist in the first place around the rotary balancer, only gas (compressible fluid) such as air, which has a significantly smaller density than lubricating oil, exists.
Stirring resistance by the rotating balancer is not a problem, and there is no problematic power loss. For this reason, the shape of the rotary balancer used in the conventional scroll compressor for fuel cells is determined based on the moment of inertia and the storage space in the housing, and as shown in FIG. It was often a fan-shaped plate member.

[0005] However, as the development of the scroll compressor for fuel cells has progressed, problems which have not been a problem of the conventional scroll compressor have come to occur in the scroll compressor for fuel cells. In other words, since the environment in which the fuel cell is used is often a quiet environment in which all the devices are driven by electricity, noise reduction has also been strictly required for the fuel cell scroll compressor. . For example, when an electric vehicle powered by a fuel cell is considered, the electric motor as its power source is quiet, unlike the internal combustion engine that is a conventional noise source, so that noise generated from the fuel cell portion is highlighted. It became so. Electric vehicles are also provided with soundproofing materials for insulating road noise, etc., but the frequency range of noise absorbed by the soundproofing materials is generally limited, and noise in low frequency ranges is not much absorbed. Often not. For this reason, when the noise generated by the scroll compressor for a fuel cell includes a noise in a low frequency range, the noise may not be sufficiently absorbed by the soundproofing material. In this case, the noise generated from the scroll compressor for the fuel cell enters the vehicle interior without being interrupted, even though other noises are interrupted, so that the noise may be more annoying. .

Under such circumstances, the present inventor has conducted intensive research and found that the wind noise generated by the rotary balancer of the scroll compressor for a fuel cell is a large noise source. Such a problem is a problem peculiar to a scroll type compressor for a fuel cell, and needless to say, none of the above-mentioned publications describes such a problem at all. In JP-A-59-79086, the problem is different from that of the scroll type compressor described in the above-mentioned publication, and the balancer mechanism is devised to provide a main bearing and a slewing bearing (eccentric bearing in the present invention). A rotary balancer in which a centrifugal force is not applied is disclosed. However, the scroll compressor disclosed in this publication is not intended for a scroll compressor for a fuel cell, but is premised on being used for a car air conditioner. That is, it is considered that the periphery of the rotary balancer is lubricated by the forced lubrication by the lubricating oil or the circulation of the refrigerant mixed with the lubricating oil. Also, this publication does not disclose or suggest any problems specific to the above-described scroll compressor for fuel cells.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a scroll compressor for a fuel cell, which can suppress wind noise caused by a rotating balancer and reduce noise generation. I do.

[0008]

The inventor of the present invention has intensively studied to solve this problem, and as a result of repeated trial and error, as a result of the rotation of the rotating balancer, the rotating balancer contacts the surrounding gas when rotating. The inventors came up with the idea of making the contact surface a smooth curved surface, and completed the scroll compressor for a fuel cell of the present invention. (1) That is, a scroll compressor for a fuel cell according to the present invention comprises a drive motor serving as a drive source, a main shaft connected to a drive shaft of the drive motor, and an eccentric extending from the main shaft and provided eccentrically to the main shaft. A drive crankshaft having a shaft portion, a fixed scroll fixed to the housing having a fixed spiral portion erected from the fixed base, and meshing with the fixed scroll portion of the fixed scroll erected from one side of the revolving base. An orbiting scroll having an orbiting spiral portion and an eccentric bearing portion for pivotally supporting the eccentric shaft portion on the other side of the orbiting base; and reducing imbalance caused by the orbiting scroll orbiting around the main shaft portion. A rotary balancer provided to perform the operation, and the gas is sucked into a compression chamber formed by the fixed scroll and the orbiting scroll by the orbiting motion of the orbiting scroll, and Supplying compressed gas to the fuel cell electrodes by condensation discharge, in the scroll type compressor for a fuel cell that lubrication by lubricant oil is not performed, the rotary balancer,
It is substantially fan-shaped, and is characterized in that at least a part of a front end surface which comes into contact with surrounding gas during rotation is formed of a smooth curved surface.

As described above, the present inventors have found that the noise source of the scroll compressor for a fuel cell is in the rotary balancer, and more specifically, that the wind noise caused by the rotation of the rotary balancer is a noise source. stopped. Here, since the wind noise is also a sound wave (pressure wave), it is considered that the atmospheric pressure fluctuation around the rotating balancer is the main cause of the wind noise. Therefore,
In order to reduce the wind noise, that is, to reduce the pressure fluctuation, the airflow generated by the rotation of the rotating balancer is made to flow as smoothly as possible without separating from the surface of the rotating balancer. If it is effective to reduce wind noise as much as possible,
The inventor has thought. In the fuel cell scroll compressor according to the present invention, when the rotary balancer has a substantially fan shape, at least a part of the front end surface which comes into contact with the surrounding gas at the time of rotation has a smooth curved surface. , A smooth airflow can be generated from the rear to the rear, and pressure fluctuations occurring around the rotary balancer can be suppressed. Thus, it is considered that the wind noise, that is, the noise generated from the scroll compressor for the fuel cell could be reduced.

Further, it is more preferable that the rotary balancer has at least a part of a rear end face located on a side opposite to the front end face formed of a smooth curved surface. When the rotary balancer rotates, the air pressure tends to rise on the front end face side, whereas the air flow is turbulent due to the generation of vortex and the air pressure drops on the rear end face side opposite thereto. All of these cause fluctuations in the air pressure around the rotary balancer. In the case of the present invention, at least a part of the rear end surface in addition to the front end surface has a smooth curved surface, so that the separation of the airflow is further suppressed, and A smooth air flow is obtained, and fluctuations in atmospheric pressure are suppressed.
Therefore, the noise can be further reduced.

(2) By making the rotary balancer substantially fan-shaped, not only the shape can be simplified, but also the mass can be easily concentrated to increase the moment of inertia.
The shape of the rotary balancer is not limited to a fan shape, as long as the imbalance caused by the orbiting movement of the orbiting scroll can be reduced or eliminated, for example,
It may be substantially columnar or cylindrical. That is, the scroll compressor for a fuel cell of the present invention includes a drive motor serving as a drive source, a main shaft portion connected to a drive shaft of the drive motor, and an eccentric shaft portion extending from the main shaft portion and provided eccentrically to the main shaft portion. A fixed scroll fixed to the housing and having a fixed spiral portion erecting from the fixed base, and a swirling spiral portion erecting from one side of the swiveling base and meshing with the fixed spiral portion of the fixed scroll. And an orbiting scroll having an eccentric bearing portion for pivotally supporting the eccentric shaft portion on the other side of the orbiting base; and for reducing imbalance caused by the orbiting scroll orbiting around the main shaft portion. A rotary balancer provided, and a gas is sucked into a compression chamber formed by the fixed scroll and the orbiting scroll by the orbital movement of the orbiting scroll, and the gas is compressed and discharged by the orbiting motion. In a fuel cell scroll compressor in which a compressed gas is supplied to an electrode of the fuel cell and lubrication by a lubricating oil is not performed, the rotary balancer has a substantially columnar shape or a substantially cylindrical shape. The outer peripheral surface abutting on the surface may be formed of a continuous smooth curved surface.

The rotary balancer is substantially columnar or substantially cylindrical,
By making the outer peripheral surface in contact with the surrounding gas at the time of rotation a continuous smooth curved surface, the airflow generated around the rotary balancer can be made even smoother than in the case of the above-described substantially fan-shaped. . Therefore, it is possible to further suppress the atmospheric pressure fluctuation, that is, reduce the noise.

[0013]

Next, the present invention will be described in more detail with reference to embodiments. (1) The rotary balancer is provided to reduce imbalance caused by the orbiting scroll orbiting around the main shaft portion. However, the rotating balancer according to the present invention is not limited to one that directly cancels imbalance based on centrifugal force acting on the orbiting scroll.
That is, the "rotary balancer" according to the present invention is not only a balancer (balance weight) provided on the drive crankshaft and rotated integrally with the drive crankshaft, but also follows the orbiting motion of the orbiting scroll. A balancer (balance weight) provided on the driven crankshaft, and also a balancer (trim weight) provided for balancing the drive crankshaft and the driven crankshaft in the axial direction (balance of moment with the axis as a lever). Including. Also, as disclosed in Japanese Patent Application Laid-Open No. 2000-145669, the present invention can be applied to a case where each balance weight is divided and arranged.

Here, since the moment of inertia of the orbiting scroll in which the mass is widely distributed is very large, usually, the moment of inertia of the rotary balancer provided on the drive crankshaft to directly balance the moment of inertia is large. , Which is still big. Since there is a demand for downsizing of the compressor as a whole, the center of gravity of the rotating balancer cannot be brought to a position far from the rotating shaft, and the projected area of the rotating balancer (the area in contact with the surrounding gas) is naturally determined. It gets bigger. Therefore, in the scroll compressor for a fuel cell, the noise that is most likely to be caused by the wind noise is the rotary balancer that rotates integrally with the drive crankshaft. Therefore, in the scroll compressor for a fuel cell according to the present invention, when the rotary balancer is provided on the drive crankshaft and rotates integrally with the drive crankshaft, it is more effective for noise reduction. .

By the way, it may be difficult to achieve both the miniaturization of the rotary balancer and the securing of the moment of inertia while making the surface of the rotary balancer which comes into contact with the surrounding gas during rotation into a smooth curved surface. In such a case, the scroll compressor for a fuel cell according to the present invention is preferably configured such that at least a part of the rotary balancer is made of a material having a higher density than the drive crankshaft. In this case, the entire rotary balancer may be formed of a material having a high density, or the rotary balancer and the drive crankshaft may be integrally formed, and a member having a high density may be provided at a position away from the rotary shaft of the rotary balancer. May be attached separately. For example, the drive crankshaft made of steel (density: 7.8 g / cm ³ or so) when it, made a rotation balancer brass (brass) (Density: 8.4 g / cm ³ or so) and or tungsten (density: 19 0.4 g / cm
³ ) may be partially attached to the outermost periphery of the rotary balancer.

(2) In particular, when the rotary balancer has a substantially columnar or substantially cylindrical shape, mass may be present on the side opposite to the position where it originally exists. For this reason, if the entire rotating balancer is uniform in mass, the inertia moment due to the balance weight is reduced, and the balance weight is enlarged. Therefore, when the rotating balancer has a high-mass portion and a low-mass portion, it is possible to reduce the size of the substantially columnar or substantially cylindrical rotating balancer while suppressing a necessary reduction in the moment of inertia.

For example, in the case of a rotary balancer provided on a drive crankshaft, it is preferable to arrange a high-mass portion on the side opposite to the eccentric shaft portion and a low-mass portion on the eccentric shaft portion side. In addition, a rotary balancer having a high-mass part and a low-mass part can be obtained by, for example, joining a high-density member and a low-density member. Specifically, the high mass part can be made of a metal material and the low mass part can be made of a resin material. Further, when the entire rotating balancer is formed of the same material, for example, if the low mass portion is a hollow portion, there is no need to use a different material,
It is suitable.

When the rotary balancer has a substantially columnar or substantially cylindrical shape, the eccentric bearing of the orbiting scroll has:
The rotary balancer projects cylindrically, has an insertion port inserted on the outer peripheral side of the eccentric bearing part and is provided on the drive crankshaft, and the rotary balancer inserts the insertion port into the eccentric bearing part. It is preferable to rotate integrally with the drive crankshaft in this state, because the size in the axial direction can be reduced.

(3) Regardless of whether the rotary balancer has a substantially fan shape, a substantially columnar shape or a substantially cylindrical shape, the shape of the smooth curved surface that comes into contact with the surrounding gas during rotation is not particularly limited. The whole or a part may be a circumferential surface, an elliptical surface, or a streamlined surface. Further, the fuel cell in which the scroll compressor according to the present invention is used includes:
There are alkaline aqueous solution type, solid polymer type, phosphoric acid type, molten carbonate type, solid electrolyte type and the like. In addition, it can be used in various fields, such as for electric vehicles and household power generation, and can be used in various fields. In particular, the present invention is applied to fuel cells (for example, electric vehicles and the like) that require quietness. It is preferable to use a scroll compressor for a fuel cell.

[0020]

Next, the scroll compressor for a fuel cell according to the present invention will be described in more detail with reference to examples. (Overall Structure of Scroll Compressor for Fuel Cell) FIG.
A scroll type air compressor 100 for a fuel cell according to an embodiment of the present invention (hereinafter, simply referred to as “compressor 100”).
A cross-sectional view of FIG. The compressor 100 roughly includes a compression mechanism, a crank mechanism, and a drive motor. Hereinafter, each will be described specifically. The compression mechanism includes the fixed scroll 110 and the orbiting scroll 1
20. The fixed scroll 110 includes a disc-shaped fixed base 110a, a spiral fixed spiral part 110b erected from the fixed base 110a, and an outer peripheral wall 110c that covers the fixed spiral part 110b. The fixed base 110a and the outer peripheral wall 110c are integrated to form a front housing. Note that a discharge port 111 connected to the oxygen electrode of the fuel cell is provided at the center of the fixed base 110a.

The orbiting scroll 120 also includes a disk-shaped orbiting base 120a and a spiral orbiting spiral part 120b standing upright from the orbiting base 120a.
A cylindrical eccentric bearing portion 120c with a bottom is provided at the center on the rear side, and a cylindrical eccentric bearing portion 120d with a bottom is provided evenly at three locations on the outer peripheral side. The crank mechanism section includes a drive crank mechanism 140 that causes the orbiting scroll 120 to perform a orbiting motion (orbital motion), and a driven crank mechanism 150 that prevents the orbiting scroll 120 from rotating.

The drive crank mechanism 140 comprises the above-described eccentric bearing portion 120c, a crankpin 131a (corresponding to an eccentric shaft) of the drive crankshaft 131, and a grease-enclosed roller bearing 137 that supports the crankpin 131a. You. The crankpin 131a is rotatably supported by a roller bearing 137 housed in the eccentric bearing 120c.

The driven crank mechanism 150 includes the eccentric bearing 120d, a crankpin 151a of the driven crankshaft 151, and a grease-enclosed radial ball bearing 153 that supports the crankpin 151a. The radial ball bearing 153 housed in the eccentric bearing portion 120d uses the crank pin 151a.
Is rotatably supported.

Further, the drive crankshaft 131 is supported on the front side by a grease-enclosed ball bearing 138. The rear side of the driven crankshaft 151 is supported by a grease-enclosed ball bearing 152. By the way, in order to cancel the moment of inertia generated when the orbiting scroll 120 orbits, the balance weight W (corresponding to a rotary balancer) is driven by the drive crankshaft 1.
31 is provided on the flange surface 131f provided on the main shaft portion 131b.
It is fixed with a bolt (not shown). The shape of the balance weight W will be described later.

The driven crankshaft 151 is provided with a balance weight 151b.
The vibration associated with the turning motion of 20 is reduced. This balance weight 151b may be used as a characteristic rotating balancer in the present invention. The crank mechanism is housed in the center housing 170 together with the drive motor. The crank frame and the drive motor are integrated with the support frame 1 which is integrally formed substantially at the center of the center housing 170.
It is partitioned by 71. The above-described ball bearing 138 and ball bearing 152 are fitted into the support frame 171.

The drive motor section includes a center housing 17
0, a rear housing 190, and a drive motor 130 housed between them. Drive motor 1
Reference numeral 30 denotes a drive shaft 131c penetrating the center of the shaft, a rotor 133 fitted into the drive shaft 131c, and a stator 1 provided on the outer peripheral side thereof and wound with a coil 135.
And an inverter (not shown) whose rotation speed and the like can be controlled. further,
Center housing 170 covering this drive motor 130
A water jacket 172 is provided substantially at the center of the drive motor 13 in accordance with the position of the stator 134.
0 is cooled by cooling water.

Further, the drive shafts 13 before and after the rotor 133
Trim weights 132a and 132b are provided on 1c to balance the moment of inertia of the drive crankshaft 131 in the axial direction (direction in which the axis is bent). The trim weights 132a and 132b are usually thin plate-like shapes, and generate little wind noise due to rotation. However, the trim weights 132a and 132b may be used as characteristic rotary balancers in the present invention. In this embodiment,
Drive shaft 131c of drive motor 130 and drive crankshaft 1
The main shaft portion 131b and the crankpin 131a of the 31 constitute a drive crankshaft 131 integrally.

At the rear end of the drive motor 130, a rear housing 190 is fixed to the center housing 170 by bolts, and a motor chamber for accommodating the drive motor 130 is formed therebetween. In the center of the rear housing 190, the drive shaft 131c of the drive crankshaft 131 is supported by a ball bearing 139 and the seal member 13
6 sealed.

When electric power is supplied to the drive motor 130, the drive crankshaft 131 rotates, and the orbiting scroll 120 orbits while engaging with the fixed scroll 110 via the drive crank mechanism 150. Then, air is sucked from a suction port (not shown) into a compression chamber formed between the fixed scroll 110 and the orbiting scroll 120,
The sucked air is compressed along with the turning of the orbiting scroll 120 and is discharged from the discharge port 111 to supply compressed air to the oxygen electrode of the fuel cell.

(Rotary Balancer) By the way, an embodiment of the rotary balancer which is a feature of the present invention will be described in detail with reference to FIGS. FIG. 2 shows a balance weight 200 which is a first embodiment of the rotary balancer (balance weight W) according to the present invention. FIG. 2A is a perspective view showing the entire balance weight 200, and FIG. 1B is a perspective view of the balance weight 200 shown in FIG.
It is a perspective view showing A section. This balance weight 20
Reference numeral 0 denotes a substantially cylindrical member as a whole provided with an insertion port 230 which is inserted from the outer peripheral side of the eccentric bearing portion 120c at substantially the center. The outer peripheral surface with which the gas comes into contact during rotation is formed by a smooth circumferential curved surface.

A flange surface 131f of a main shaft portion 131b of the drive crankshaft 131 is provided at one of the insertion ports 230.
There are provided four mounting holes 250 for mounting on the base.
The external appearance of the balance weight 200 is cylindrical (pillar) having the outer peripheral side surface 260 as both bottom surfaces. As can be seen from the cross-sectional portion of FIG. 2B, the low mass portion 210 and the high mass portion 220 are understood. And is formed from And the low mass part 2
Reference numeral 10 is formed by a hollow portion. The balance weight 200 is made of brass while the drive crankshaft 131 is made of steel, and the low-mass part 210 and the high-mass part 220 are made of the same material (brass). In addition,
In the balance weight 200, a flange 240 is further provided on the outer peripheral side of the high mass portion 220 in order to take a large moment of inertia.

A balance weight 300 which is a second embodiment of the rotary balancer (balance weight W) according to the present invention.
Is shown in FIG. FIG. 7A is a front perspective view showing the entire balance weight 300, and FIG. 7B is a rear perspective view. The description of the same parts as the balance weight 200 is omitted.

The balance weight 300 is similar to the balance weight 200, similarly to the low-mass part 310 and the high-mass part 3.
20 and the low mass portion 310 also forms a hollow portion, but the shape of the hollow portion is different. That is, it is not a closed hollow part but an open hollow part, and its cross section has a concave shape. With such a shape, the balance weight 300 can be easily manufactured.

Here, it is considered that the airflow may be disturbed by forming the low-mass part 310 as an open hollow part to cause wind noise, but actually, the gas existing in the hollow part is considered. Since the (air) rotates integrally with (rotates with) the balance weight 300, the wind noise does not substantially increase. If it is desired to eliminate a slight influence, a lightweight resin (for example, styrene foam) may be embedded in the hollow portion. In FIG. 3, the cross section of the low mass portion 310 is a concave shape, but a hollow portion may be formed on both the front and back surfaces as a concave shape.

A balance weight 400 which is a third embodiment of the rotary balancer (balance weight W) according to the present invention.
Is shown in FIG. FIG. 4 is a perspective view showing the whole of the balance weight 400. The balance weight 400 has a substantially fan-shaped solid plate shape, and is made of brass like the balance weight 200 and the like. The inner peripheral side surface 430 of the balance weight 400 is formed along the outer peripheral surface of the eccentric bearing portion 120c, and a stepped portion connected to the inner peripheral side surface 430 is attached to the flange surface 131f of the drive crankshaft 131. Are provided at four locations. Further, its outer peripheral side is formed thicker so as to increase the moment of inertia. By the way, the front end face 410 with which the airflow comes into contact when the balance weight 400 rotates and the rear end face 420 on the opposite side are formed by a smooth circumferential curved surface. As a result, the gas that comes into contact during rotation is caused to flow smoothly from the front to the rear, suppressing fluctuations in atmospheric pressure and reducing noise.

(Noise Analysis) The balance weight 200 shown in FIGS. 1 and 2 and the conventional balance weight 600 shown in FIG. 6 were attached to the above-described scroll compressor 100 for a fuel cell, and the noise in each case was measured. Since the level (first-order rotation component) was measured, the result is shown in FIG. This measurement was performed using a microphone and a sound level meter.
Each noise level was measured by changing the noise level every 500 rpm in the range of 000 to 5000.

As can be seen from FIG. 5, the use of a balance weight in which the contact surface with which the air flow contacts is formed with a smooth curved surface significantly reduces the noise level as the rotation speed increases. In particular, at 5000 rpm, noise is reduced by 10 dB by using the rotating balancer according to the present invention. This means that the noise has been reduced to about 1/3 in terms of sound pressure. In particular, since the first-order component having a low frequency that is difficult to shield with a soundproof material or the like is low, this embodiment can be an effective means for reducing noise in a vehicle interior or the like. In this embodiment, three driven crank mechanisms 150 are provided as rotation preventing mechanisms for the orbiting scroll 120. In connection with this, the noise of the rotation third-order component is about 5 dB (5000 rpm).
m) It has been confirmed that it decreases.

[0038]

According to the scroll compressor for a fuel cell of the present invention, the surface of the rotary balancer which comes into contact with the surrounding gas during rotation is formed with a smooth curved surface, so that the airflow around the rotary balancer becomes smooth. Noise such as wind noise could be significantly reduced.

[Brief description of the drawings]

FIG. 1 is an overall view of a scroll compressor for a fuel cell according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a balance weight according to the first embodiment of the rotary balancer, wherein FIG. 2 (a) is an overall perspective view and FIG. 2 (b) is a sectional view thereof.

FIG. 3 is a perspective view showing a balance weight according to a second embodiment of the rotary balancer, wherein FIG. 3 (a) is an overall perspective view on the front side and FIG. 3 (b) is an overall perspective view on the back side.

FIG. 4 is a perspective view showing a balance weight which is a third embodiment of the rotary balancer.

FIG. 5 is a graph comparing noise levels of the rotary balancer according to the present invention and a conventional rotary balancer.

FIG. 6 is a view showing a balance weight which is a conventional rotary balancer.

[Explanation of symbols]

110 Fixed Scroll 120 Orbiting Scroll 120c Eccentric Bearing 130 Drive Motor 131 Drive Crankshaft W, 200, 300, 400 Balance Weight (Rotary Balancer) 210 Low Mass 220 High Mass 230 Insertion Port 410 Front End 420 Rear End

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiro Fujii 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Ryuta Kawaguchi 2-1-1, Toyota-cho, Kariya-shi, Aichi Pref. Inside Toyota Industries Corporation (72) Inventor Tsutomu Nasuda 2-1-1 Toyotamachi, Kariya City, Aichi Prefecture F-term inside Toyota Industries Corporation (Reference) 3H029 AA02 AA15 AA24 AB05 BB24 BB32 3H039 AA06 AA10 AA12 BB02 CC02 CC20 5H027 AA02 BC11

Claims (8)

[Claims] 1. A drive base comprising: a drive motor serving as a drive source; a drive crankshaft having a main shaft connected to a drive shaft of the drive motor; an eccentric shaft extending from the main shaft and provided eccentrically to the main shaft; A fixed scroll fixed to the housing and having a fixed scroll portion standing upright from the rotating scroll; and a rotating scroll portion raised from one side of the rotating base and engaged with the fixed scroll portion of the fixed scroll; An orbiting scroll having an eccentric bearing portion for pivotally supporting the eccentric shaft portion, and a rotary balancer provided to reduce imbalance caused by the orbiting scroll orbiting around the main shaft portion, Gas is sucked into a compression chamber formed by the fixed scroll and the orbiting scroll by the orbiting motion of the orbiting scroll, and the gas is compressed and discharged to supply a compressed gas to the electrode of the fuel cell. In the scroll compressor for a fuel cell, which is not lubricated by a lubricating oil, the rotary balancer has a substantially fan shape, and at least a part of a front end surface which comes into contact with surrounding gas during rotation has a smooth curved surface. A scroll compressor for a fuel cell, comprising: 2. A scroll compressor for a fuel cell according to claim 1, wherein said rotary balancer has a smooth curved surface at least a part of a rear end face located on a side opposite to said front end face. 3. A drive crankshaft having a drive motor serving as a drive source, a main shaft portion connected to a drive shaft of the drive motor, an eccentric shaft portion extending from the main shaft portion and provided eccentrically to the main shaft portion, and a fixed base. A fixed scroll fixed to the housing and having a fixed spiral portion standing upright, a swirling spiral portion erecting from one side of the turning base and meshing with the fixed scroll portion of the fixed scroll, and a rotating scroll portion on the other side of the turning base. An orbiting scroll having an eccentric bearing for pivotally supporting the eccentric shaft, and a rotary balancer provided to reduce imbalance caused by the orbiting scroll orbiting around the main shaft. Gas is sucked into a compression chamber formed by the fixed scroll and the orbiting scroll by the orbiting motion of the orbiting scroll, and the gas is compressed and discharged to supply a compressed gas to the electrode of the fuel cell. In a scroll compressor for a fuel cell that is not lubricated by a lubricating oil, the rotary balancer has a substantially columnar or substantially cylindrical shape,
A scroll compressor for a fuel cell, characterized in that an outer peripheral surface that comes into contact with surrounding gas during rotation is formed of a continuous smooth curved surface. 4. The scroll compressor according to claim 3, wherein the rotary balancer has a high-mass part and a low-mass part. 5. The low mass part comprises a hollow part.
The scroll-type air compressor for a fuel cell according to the above. 6. The fuel cell scroll compressor according to claim 1, wherein the rotary balancer is provided on the drive crankshaft and rotates integrally with the drive crankshaft. 7. A scroll compressor for a fuel cell according to claim 6, wherein at least a part of said rotary balancer is made of a material having a higher density than said drive crankshaft. 8. The eccentric bearing portion of the orbiting scroll projects cylindrically, and the rotary balancer has an insertion port inserted on the outer peripheral side of the eccentric bearing portion and is provided on the drive crankshaft, 4. The scroll compressor according to claim 3, wherein the rotary balancer rotates integrally with the drive crankshaft with the insertion opening inserted into the eccentric bearing.