JP2003247494A - Fluid machinery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid machinery in which despite a low parts-count, miniaturization can be achieved, besides a high-speed rotation is made possible. <P>SOLUTION: In this fluid machinery, suction and discharge of gas is performed by synchronously rotating a pair of pump rotors 36, 38 housed in a pump casing 32 in the reverse direction to each other by means of a built-in motor 10. The pump rotors 36, 38 each are coupled respectively to free ends of a pair of rotation shafts 40, 42 supported rotatably in a manner of cantilevers. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-free type fluid machine for compressing and transferring gas in a non-lubricated state, and in particular, it is an optimum roots type used as a blower for compressing and transferring combustible gas. And other positive displacement biaxial fluid machines.

[0002]

2. Description of the Related Art For example, a displacement type two-shaft fluid machine which is optimally used as a blower for compressing and transferring gas such as air and combustible gas includes a roots type, a tooth (decad shaped rotor) type,
There are various types such as screw type. Here, for example, a roots-type blower includes a pair of pump rotors (roots rotors) that rotate in synchronization in opposite directions, and the pump rotors are housed in a pump chamber of a pump casing and rotated in synchronization in opposite directions. The gas is sucked into the pump chamber, pressurized, and discharged.

The pair of pump rotors are attached to, for example, a pair of rotating shafts arranged in parallel with each other. Then, a pair of timing gears meshing with each other is fixed to this rotating shaft, and one rotating shaft is directly connected to, for example, a motor so that the pair of pump rotors attached to the pair of pump rotors rotate synchronously in opposite directions. It has become. Each of these rotary shafts is arranged so as to cross the pump chamber of the pump casing, and on both sides sandwiching the pump rotor,
It is rotatably supported by the pump casing via bearings.

In order to secure the pressure in the pump chamber,
The clearance between the pump rotors and between the pump rotor and the pump casing is, for example, 0.02 to 0.04.
It is set to mm.

[0005]

In a conventional positive displacement biaxial fluid machine such as a roots type blower, a rotary shaft to which a pump rotor is attached is disposed on both sides of the pump rotor with bearings interposed between the pump casing and the pump casing. Since the rotary shaft is rotatably supported on the pump rotor, the rotary shaft projects toward the non-motor side of the pump rotor, and the pump casing needs to accommodate a bearing that supports the rotary shaft projected toward the non-motor side. ,
Not only the length along the axial direction is increased, but also the weight is increased, which makes it difficult to reduce the size and weight.

Further, when the clearances between the pump rotors and between the pump rotor and the pump casing are set to the above values, it is necessary to accurately control the coaxiality of the bearings at the distant positions with the pump rotor interposed therebetween. However, there were structural limitations. Further, when the coaxiality is poor, there is a problem that a so-called "galling" phenomenon occurs between the pump rotors and between the pump rotor and the pump casing.

The present invention has been made in view of the above, and an object of the present invention is to provide a fluid machine which can be reduced in size and weight while reducing the number of parts, and can be rotated at a higher speed.

[0008]

According to a first aspect of the present invention, a pair of pump rotors housed in a pump casing are rotated in synchronism with each other in opposite directions via a motor incorporated therein to suck gas. In the fluid machine configured to discharge the fluid, each of the pump rotors is cantilevered by connecting to the free ends of a pair of rotatably supported rotating shafts. In this way, the pair of pump rotors housed in the pump casing are cantilevered by connecting to the free ends of the pair of rotary shafts, respectively, so that the rotary shaft does not project to the side opposite to the motor of the pump rotor. Accordingly, the length along the axial direction can be shortened and the weight can be reduced accordingly.

According to a second aspect of the present invention, at least one of the pair of rotary shafts is connected to the output shaft of the motor through a coupling arranged near the motor rotor portion of the motor. The fluid machine according to claim 1. Thus, by disposing the coupling that connects the rotary shaft and the output shaft of the motor in the vicinity of the motor rotor portion of the motor, the total length of the fluid machine can be further shortened.

The invention according to claim 3 is the fluid machine according to claim 2, wherein an elastic body shaft joint in which an elastic body is interposed between a pair of joint pieces is used as the coupling. . Thereby, even if there is an error (deviation) between the shaft center of the motor output shaft and the shaft center of the rotating body, the rotating shaft is connected to the output shaft of the motor by absorbing this error by the elastic body. In addition, there is no need for centering at the time, and the heat insulation of the motor is blocked by the heat insulation effect of the elastic body, so that the influence of the thermal expansion of the pump casing of the pump section and the pump rotor, It is possible to prevent a decrease in pump efficiency due to a decrease in gas density due to an increase in the temperature of the handled gas.

According to a fourth aspect of the present invention, there is provided a bracket that connects the pump casing and the motor, and the bracket also serves as a bearing housing that accommodates a load side bearing of the motor. The fluid machine according to any one of 1 to 3. As a result, it is not necessary to separately provide a bearing housing for accommodating the bearing on the load side of the motor, so that the number of parts and the number of working steps can be reduced, and the total length of the fluid machine can be further shortened.

According to a fifth aspect of the present invention, a box portion is integrally connected to the pump casing, and the pair of rotary shafts are respectively inserted into the through holes provided in the pump casing and the box portion to rotate. The fluid machine according to any one of claims 1 to 4, wherein the fluid machine is supported freely. This makes it possible to form the through holes of the pump casing and the box portion by so-called concentric processing, and thus, by forming the through holes of the pump casing and the box portion by concentric processing to increase the concentricity, It is possible to facilitate the assembling work and reduce the number of parts, prevent the swing of the pump rotor, and perform stable operation.

According to a sixth aspect of the present invention, there is provided a pair of timing gears which are fixed to the pair of rotary shafts and mesh with each other, and the timing gears are housed in the box portion. Is a fluid machine. As a result, the timing gear can be arranged in the central portion to achieve balance and contribute to space saving.

According to a seventh aspect of the present invention, in fixing the timing gear to the rotary shaft, a hollow truncated cone-shaped collet having a slit and a tapered outer peripheral surface and an inner peripheral surface of the collet are provided. And a stopper having a hollow portion that is a reverse tapered surface opposite to the tapered surface, and the timing gear and the stopper are fixed by tightening a bolt, and the collet is elastically deformed with the tightening of the bolt. 7. The fluid machine according to claim 6, wherein the rotary shaft is tightened by tightening the rotary shaft.

Thus, the rotary shaft is inserted through the stopper having the collet arranged in the hollow portion and the timing gear, and the bolt is fastened to fix the timing gear and the stopper, thereby elastically deforming the collet to fasten the rotary shaft. The stopper can be fixed to the rotary shaft via.
As a result, the timing gear can be fixed at any position along the axial direction of the rotary shaft, and fine adjustment of the fixed position of the timing gear can be performed easily and reliably.

The invention according to claim 8 is the fluid machine according to any one of claims 1 to 7, characterized in that the rotary shaft is biased in one direction along the axial direction. As a result, it is possible to prevent vibration along the axial direction of the rotary shaft, adjust the clearance between the pump casing and the pump rotor during assembly, and keep this clearance constant during operation.

According to a ninth aspect of the invention, in fixing the rotating body to the rotating shaft so as to rotate integrally with the rotating shaft,
A hollow truncated cone-shaped collet having a slit and an outer peripheral surface having a taper surface, and a stopper having a hollow portion having an inner peripheral surface having an inverse taper surface facing the taper surface of the collet, and the rotating body, A fixing structure for a rotating body, characterized in that the stopper is fixed by tightening a bolt, and the tightening of the bolt causes the collet to elastically deform to tighten the rotating shaft.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 to 5 show a fluid machine according to an embodiment of the present invention applied to a roots type blower of a biaxial fluid machine. This roots type blower (fluid machine) uses a motor 1
0 and a pump unit 12, and is mainly composed of a blower body 16 in which the motor 10 and the pump unit 12 are integrally connected via a bracket 14, and a muffling box 18 in which the blower body 16 is housed. Has been done.

The motor 10 has a motor rotor portion 20 and a motor stator portion 22. An output shaft (spindle) 24 is integrally fixed inside the motor rotor portion 20, and the motor stator portion 22 is connected to a motor frame 26. It is fixed to the inner surface. The output shaft 24 is positioned on both sides of the motor rotor portion 20 and is rotatably supported via a motor anti-load side bearing 28 housed in the motor frame 26 and a motor load side bearing 30 housed in the bracket 14. As the motor 10 is driven, it rotates integrally with the motor rotor section 20.

In this example, by housing the motor load side bearing 30 in the bracket 14 connecting the motor 10 and the pump portion 12, the bracket 14 causes the load side bearing 3 of the motor 10 to move.
The bearing housing for accommodating 0 is also used. With such a configuration, it is not necessary to provide a bearing housing for accommodating the bearing on the load side of the motor 10, the number of parts and the number of working steps are reduced, and a fluid machine corresponding to the thickness of the bearing housing is provided. The total length of can be shortened.

The pump portion 12 has a pump casing 32 that defines a pump chamber 32a therein and a pump cover 34 that closes an opening of the pump casing 32. Inside the pump chamber 32a, a pair of pump rotors is provided. (Roots rotors) 36 and 38 are housed at positions facing each other. Here, the pump casing 32 and the pump rotors 36 and 38 are disposed between the outer peripheral edges of the pump rotors 36 and 38 and the inner wall of the pump casing 32, and the pump rotor 3.
6 and 38 are formed in such a shape that a slight clearance is formed between them and are arranged at predetermined positions. The pump casing 32 includes a pair of pump rotors 36, 38.
And a suction port 32b and a discharge port 32c are provided at positions laterally opposite to each other.

In this example, as the pump rotors 36 and 38, a three-leaf type having a three-leaf shape is used, and when the pump rotors 36 and 38 rotate in the opposite direction in synchronization, gas is introduced from the suction port 32b into the pump chamber. Inhaled inside 32a,
The sucked gas is trapped between the pump rotors 36 and 38 and the pump casing 32, transferred to the discharge side, and sequentially discharged from the discharge port 32c. In the three-lobed pump rotors 36 and 38, one pump rotor has three troughs, and therefore the pump is exhausted six times per revolution. It is needless to say that the pump rotor may be a cocoon-shaped two-leaf type, four-leaf type or more, and further, multi-leaf type of 10 or more leaves. In this way, by increasing the number of leaves of the pump rotor, the pulsation of the discharged fluid can be reduced and the pump efficiency can be improved.

The pump rotors 36, 38 are cantilevered by being connected to the free ends of the rotary shafts 40, 42 arranged in parallel with each other. Here, one rotating shaft 40 serves as a drive shaft, and the other rotating shaft 42 serves as a driven shaft. That is, the drive shaft (rotating shaft) 40
One end of is connected to the output shaft 24 of the motor 10 via the coupling 44, and the drive-side pump rotor 36 is connected to the opened other end. On the other hand, driven shaft (rotating shaft) 4
2 is open at both ends, and the driven pump rotor 38 is connected to the open end of the pump casing 32 side. In this way, the pump rotors 36, 38 are cantilevered by connecting to the free ends of the rotary shafts 40, 42 so that the rotary shafts 40, 42 do not project to the opposite motor side of the pump rotors 36, 38. Accordingly, the length along the axial direction can be shortened and the weight can be reduced accordingly.

The coupling 44 is provided at a position as close to the motor rotor portion 20 of the motor 10 as possible, that is, in the wall body which also serves as a bearing housing for accommodating the load side bearing 30 of the motor 10 of the bracket 14 and is provided with the recess 14a. The end of the coupling 44 is arranged in the recess 14a. In this way, by disposing the coupling 44 that connects the drive shaft 40 and the output shaft 24 of the motor 10 in the vicinity of the motor rotor portion 20 of the motor 10, the total length of the fluid machine can be further shortened.

As the coupling 44, in this example, as shown in FIG. 4, a pair of joint pieces 46, 4 having the same shape.
8 and the elastic body 5 interposed between the joint pieces 46 and 48.
0 is used, and the elastic body shaft coupling in which the torque of one joint piece 46 is transmitted to the other joint piece 48 via the elastic body 50 is used. That is, the pair of joint pieces 46, 48
A plurality of protrusions 46a and 48a which are arranged alternately in parallel to each other. The protrusions 46a of the one joint piece 46 and the protrusions 4 of the other joint piece 48 facing each other are provided.
8a, a plurality of protrusions 50a provided on the outer peripheral portion of the elastic body 50 are respectively located, and the protrusion 4 of one joint piece 46 is located.
The torque is transmitted from 6a to the convex portion 50a of the elastic body 50, and from the convex portion 50a of the elastic body 50 to the protrusion 48a of the other joint piece 48.

As described above, by using the elastic shaft coupling as the coupling 44, the output shaft 24 of the motor 10
Even if there is a deviation (error) between the axis of the shaft and the axis of the drive shaft 40, this deviation is absorbed by the elastic body 50.
The centering work for connecting the drive shaft 40 to the output shaft 24 of the motor 10 can be eliminated. Furthermore, the elastic body 50
The heat insulation of the motor 10 blocks the heat generated from the motor 10 from being transmitted to the pump section 12 side, and the thermal expansion of the pump casing 32 and the pump rotors 36, 38 of the pump section 12 and the temperature rise of the handled gas. It is possible to prevent a decrease in pump efficiency due to a decrease in gas density due to. In particular, the pump casing 32 and the pump rotors 36 and 38 are susceptible to thermal expansion because the clearance between them is extremely small, and in a gas machine, when the gas temperature rises, the gas density decreases and the efficiency is reduced. This adiabatic effect is extremely important because it causes a decrease.

At a predetermined position along the lengthwise direction of the rotary shafts 40 and 42, a pair of timing gears 5 meshing with each other.
2, 54 are fixed. As a result, the drive shaft (rotary shaft) 40 and the driven shaft (rotary shaft) 42 are rotated in synchronization in opposite directions via the timing gears 52 and 54. By using a two-axis synchronous motor to rotate the pair of rotary shafts in synchronization in opposite directions, it is possible to eliminate the need to use a timing gear.

In this example, the timing gears 52 and 54 can be fixed at arbitrary positions on the rotary shafts 40 and 42. This will be described with reference to FIG. Although FIG. 5 shows an example in which the timing gear 52 is fixed to the drive shaft 40, the same applies to the driven shaft 42.

That is, a hollow truncated cone-shaped collet 56 having a slit 56a and an outer peripheral surface having a tapered surface 56b,
The stopper 58 has a hollow portion whose inner peripheral surface is an inverse tapered surface 58a facing the tapered surface 56b of the collet 56. Then, with the collet 56 accommodated in the hollow portion of the stopper 58, the drive shaft 40 is inserted into the stopper 58 and the timing gear 52, and the stopper 58 is inserted.
With the timing gear 52 positioned at a predetermined position along the axial direction of the drive shaft 40, the bolt 60 is inserted into the hole 58b provided in the stopper 58 and tightened. As a result, the stopper 58 and the timing gear 52 are directly fastened via the bolt 60, and as the bolt 60 is fastened, the reverse taper surface 58a of the stopper 58 is secured to the collet 5.
When the collet 56 is advanced in contact with the tapered surface 56b of No. 6, the collet 56 is pressed inward in a wedge shape, the collet 56 is elastically deformed through the slit 56a, and the drive shaft 40 is tightened.

As a result, by tightening the bolt 60, the timing gear 52 and the stopper 58 are connected to each other by the bolt 60.
It is possible to fix the stopper 58 to the drive shaft 40 via the collet 56 that is directly fastened via the collet 56 and elastically deformed by tightening the bolt 60. As a result, the timing gear 52 can be fixed at an arbitrary position along the axial direction of the drive shaft 40, and fine adjustment of the fixing position of the timing gear 52 can be performed easily and accurately. That is, it is possible to make fine adjustments that cannot be achieved by fixing with a conventional general key. Moreover, by providing the tapered surface 56b on the outer peripheral surface of the collet 56 and the reverse tapered surface 58a facing the tapered surface 56b in the hollow portion of the stopper 58, the stopper 58 and the timing gear 5 on the drive shaft 40 are provided.
2 can be fixed more firmly and stably.

The rotary shafts 40 and 42 are connected to the timing gear 5
It is rotatably supported by bearings 62 and 64 on both sides sandwiching 2, 54. Here, the load side bearing 62 is accommodated in the through hole 32d provided in the pump casing 32, and the anti-load side bearing 64 is accommodated in the through hole 66a provided in the box portion 66 integrally connected to the pump casing 32. Has been done. That is, the timing gears 52 and 54 are
It is housed in the box portion 66, and is located almost at the center of the blower body 16, so that it can be balanced and contribute to the space reduction.

Further, in order to prevent the grease used as a lubricant for the timing gears 52 and 54 from flowing into the pump chamber 32a, the outer peripheral surfaces of the rotary shafts 40 and 42 and the through hole 32d of the pump casing 32 are prevented. A V ring 67 and a seal ring 68 are interposed between the inner peripheral surface and the inner peripheral surface.

As described above, the box portion 66 is integrally connected to the pump casing 32, and the timing gears 52 and 54 are accommodated in the box portion 66, whereby a gear box for accommodating the timing gear is separately provided. It is possible to reduce the number of parts and the number of processing steps as compared with. Moreover, the through hole 32d provided in the pump casing 32
By inserting the pair of rotary shafts 40 and 42 into the through holes 66a provided in the box portion 66 and rotatably supporting them, the through hole 32d of the pump casing 32 and the through hole 66a of the box portion 66 are It is possible to form by so-called concentric processing. As described above, the through hole 32d provided in the pump casing 32 and the through hole 66a provided in the box portion 66 are formed by concentric processing to increase the concentricity. It is possible to prevent the vibrations of the pump rotors 36 and 38 and to perform stable operation.

Further, a C-shaped retaining ring 70 is attached to each end of the rotating shafts 40 and 42 on the side of the motor 10, and the C-shaped retaining ring 70 and the rotating shafts 40 and 42 are rotatably supported. The compression coil springs 72 are respectively interposed between the load side bearings 64. As a result, the rotary shafts 40, 42
Is urged in the axial direction toward the motor 10 side.

In this way, by urging the rotary shafts 40, 42 toward one side (in this example, the motor 10 side) in the axial direction, the vibration of the rotary shafts 40, 42 along the axial direction is prevented. You can Moreover, the clearance along the axial direction between the pump casing 32 and the pump rotors 36, 38 can be adjusted during assembly, and this clearance can be kept constant during operation.

The sound deadening box 18 has a flat base 74.
And a box 76 that surrounds the four sides of the base 74 and surrounds the four sides, and a lid 78 that closes the upper end opening of the box 76.
And have. All the joints of the sound deadening box 18 are joined by welding, and a sound absorbing material 80 such as a sponge is attached to the inner peripheral surface of the sound deadening box 18. Further, an elastic body 8 such as rubber is provided between the box body 76 and the lid body 78.
2 is installed. This completely shuts off the inside and outside of the muffling box 18 so that the sound in the muffling box 18 does not leak outside.

Further, on the side of the muffling box 18,
A suction unit 84 and a discharge unit 86 are provided, and a silencer 88 configured by alternately arranging baffles, for example, is provided inside the muffling box 18. Further, a power cable 89 extends through the side portion of the muffling box 18. Here, the suction part 84 is opened inside the muffling box 18, the silencer 88 and the suction port 32 b of the pump casing 32 are the suction pipe 90, and the discharge port 32 c of the pump casing 32 and the discharge part 86 are the discharge pipe 9.
Two are connected respectively. As a result, the interior of the muffling box 18 constitutes a part of the pipe. The suction part 84 and the discharge part 86 are insulated from each other by using a grommet for electric wiring.

That is, when the pump rotors 36 and 38 rotate synchronously in opposite directions as the motor 10 is driven,
With the rotation of the pump rotors 36, 38, gas such as air is sucked into the muffling box 18 from the suction portion 84. The gas sucked into the muffler box 18 flows into the silencer 88, and the silencer 8
8 flows along the periphery of the motor 10 in the process of flowing into the motor 8 to cool the motor 10, and further from the silencer 88 to the suction pipe 90.
Flow into the pump chamber 32a through the pump rotor 3
6,38, the pressure is increased, and the discharge portion 86 passes through the discharge pipe 92.
It is designed to be discharged from the outside. Here, by providing the silencer 88 in the muffling box 18, it is possible to prevent particularly internal noise from leaking from the suction portion 84.

The blower body 16 is attached to a support base 94, and the support base 94 is attached to the base 74 of the sound deadening box 18 via a vibration-proof rubber 96. Further, a suction pipe 90 connecting the silencer 88 and the suction port 32b of the pump casing 32, and a discharge port 32 of the pump casing 32.
The discharge pipe 92 connecting the c and the discharge portion 86 is made of, for example, a flexible tube made of resin. As a result, the vibration generated in the blower main body 16 is suppressed by the muffler box 1.
8 to prevent noise, reduce noise and
Work efficiency can be improved.

A characteristic of the roots type blower is that vibration and noise are large. In this way, the blower body 16 integrally formed is shut off from the inside and outside of the silencer box 18.
It is housed inside to prevent the internal sound from leaking to the outside and also to prevent the vibration generated in the blower body 16 from vibrating.
This vibration and noise can be greatly reduced by preventing the noise from being absorbed by 6 and transmitted to the muffling box 18.

FIG. 6 shows another example of the muffling box 18. This is because the inside of the rectangular box 76 is
0 and 102, a filter housing portion 106 that houses the filter 104 therein, and a pair of baffles 108, for example.
a and 108b are alternately arranged to constitute a silencer 110, and a silencer section 112 and a blower main body accommodating section 114 for accommodating the blower main body 16 (see FIGS. 1 to 3) are divided into partition plates 100 and 102. Gas inlet 100
a and 102a are provided. Then, as shown by the arrow in FIG. 6, the gas such as the air sucked from the suction portion 84 (see FIG. 1) is passed through the filter 104 and the gas intake port 1
00a into the silencer portion 112, and after passing through the silencer 110 of the silencer portion 112 to be silenced, the blower body accommodating portion 114 from the gas intake port 102a.
It is designed to flow in.

According to this example, the filter 104 for filtering the gas sucked into the muffling box 18 can be integrated into the muffling box 18 without being provided outside the muffling box 18, and the muffling box 18 can be integrated. By disposing the silencer 110 inside and integrating them, it is possible to reduce the overall size.

[0043]

As described above, according to the present invention,
While reducing the number of parts, we aim to reduce the size and weight of a Roots-type positive displacement biaxial fluid machine that is optimal for use as, for example, a blower. be able to.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional front view showing an example applied to a roots-type positive displacement biaxial fluid machine according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is an exploded perspective view showing a coupling.

FIG. 5 is an exploded perspective view showing a fixing portion of the timing gear.

FIG. 6 is a perspective view showing a main part of another example of the sound deadening box.

[Explanation of symbols]

10 motors 12 Pump section 14 bracket 16 Blower body 18 silence box 20 Motor rotor part 22 Motor stator 24 Output shaft 28, 30, 62, 64 bearings 32 Pump casing 32a pump room 32b suction port 32c outlet 32d through hole 36,38 Pump rotor 40 rotating shaft (driving shaft) 42 rotating shaft (driven shaft) 44 Coupling 46,48 joint piece 46a, 48a protrusion 50 elastic body 50a convex part 52,54 Timing gear 56 collets 56a slit 56b Tapered surface 58 stopper 58a Reverse taper surface 58b hole 60 volts 66 box section 66a through hole 72 Compression coil spring 74 base 76 box 78 Lid 80 sound absorbing material 82 Elastic body 84 Suction part 86 Discharge part 88,94 silencer 90 Suction tube 92 Discharge pipe 94 Support 96 anti-vibration rubber 100,102 partition boards 104 filters 106 Filter storage 108a, 108b baffle 110 silencer 112 Silencer part 114 Blower body storage

Continued front page    (72) Inventor Yasutaka Konishi             11-1 Haneda Asahi-cho, Ota-ku, Tokyo Co., Ltd.             Inside the EBARA CORPORATION F term (reference) 3H029 AA06 AB01 CC08 CC17

Claims (9)

[Claims] 1. A fluid machine in which a pair of pump rotors housed in a pump casing are rotated in synchronism with each other in opposite directions via an internal motor to suck and discharge gas. A fluid machine characterized in that a rotor is cantilevered by connecting to a free end of a pair of rotating shafts that are rotatably supported. 2. At least one of the pair of rotating shafts,
The fluid machine according to claim 1, wherein the fluid machine is connected to an output shaft of the motor through a coupling arranged near the motor rotor portion of the motor. 3. The fluid machine according to claim 2, wherein an elastic body shaft joint in which an elastic body is interposed between a pair of joint pieces is used as the coupling. 4. A bracket for connecting the pump casing and the motor to each other, and the bracket also serves as a bearing housing for accommodating a load side bearing of the motor. The fluid machine described. 5. A box portion is integrally connected to the pump casing, and the pair of rotary shafts are inserted into the through holes provided in the pump casing and the box portion to be rotatably supported. The fluid machine according to any one of claims 1 to 4. 6. Fixed to each of the pair of rotary shafts,
The fluid machine according to claim 5, further comprising a pair of timing gears meshing with each other, the timing gears being housed in the box portion. 7. When fixing the timing gear to the rotating shaft, a hollow truncated cone-shaped collet having a slit and an outer peripheral surface having a tapered surface, and an inner peripheral surface opposite to the tapered surface of the collet are opposite to each other. A stopper having a hollow portion that is a tapered surface is provided, and the timing gear and the stopper are fixed by tightening a bolt, and with the tightening of the bolt, the collet is elastically deformed to tighten the rotating shaft. The fluid machine according to claim 6, wherein 8. The fluid machine according to claim 1, wherein the rotary shaft is biased in one direction along the axial direction. 9. A hollow frustoconical collet having a slit and a tapered outer peripheral surface, and an inner peripheral surface for fixing a rotary body to a rotary shaft so as to rotate integrally with the rotary shaft. A stopper having a hollow portion that is an inverse tapered surface that faces the tapered surface of the collet, and fixes the rotating body and the stopper by tightening a bolt, and with the tightening of the bolt, the collet elastically deforms. Then, the rotating shaft is tightened to fix the rotating body.