KR101804422B1 - Dry vacuum pump apparatus, exhaust unit, and silencer - Google Patents

Abstract

The dry vacuum pump apparatus includes a silencer capable of reducing its size in order to effectively reduce the noise of gas discharged from the final outlet and intermediate release outlet of the dry vacuum pump at a wide range of frequencies from low frequency to high frequency . The dry vacuum pump apparatus comprises a dry vacuum pump 10 having a final outlet 18 and an intermediate release outlet 19 and an outlet check valve 51 connected to the final outlet 18 and having an outlet, , An intermediate check valve (52) connected to the intermediate release outlet (19) and having an outlet, and an exhaust valve connected to an outlet of the exhaust check valve (51) and an outlet of the intermediate check valve (56), and a silencer (53) connected to the exhaust passage (56) and having an outlet connected to a final exhaust passage (56a) exhausted into the atmosphere.

Description

TECHNICAL FIELD [0001] The present invention relates to a dry vacuum pump device, an exhaust unit, and a silencer,

The present invention relates to a multi-stage roots-type dry vacuum pump, such as a multi-stage positive-displacement dry vacuum pump, which is designed to reduce the noise generated when the gas is discharged from the dry vacuum pump. To a silencer included in the dry vacuum pump to reduce noise generated when a gas is discharged from the dry vacuum pump, and a silencer included in the dry vacuum pump . The silencer is small in size and capable of attenuating noise over a wide range of frequencies.

In recent years, in a wide range of applications including semiconductor manufacturing facilities, dry vacuum pumping devices capable of operating under atmospheric pressure have been used to facilitate a clean vacuum environment. In particular, semiconductor devices are manufactured according to over 300 manufacturing steps, and there are numerous vacuum pumps used in the manufacturing process. Therefore, it is very important to reduce the footprint of the vacuum pump device in order to effectively utilize the factory site of the manufacturing factory. Particularly, attempts to reduce the width of the vacuum pump device are important, because a plurality of dry vacuum pump devices are installed side by side in a number of applications. In order to reduce the pipe resistance between the vacuum pump and the semiconductor manufacturing apparatus, since vacuum pumps are sometimes installed in the semiconductor manufacturing apparatus, it is important to reduce the size of the vacuum pumps.

The dry vacuum pump device generates noise when the gas is discharged from the vacuum pump. To reduce noise, a silencer should be included at the exhaust of the vacuum pump. Silencers are available in two types: expansion type and resonance type. The inflatable silencer can prevent (reduce) noise at a wide range of frequencies. However, since the frequency that can be blocked by the expansion type silencer is inversely proportional to the length of the silencer, when the expansion silencer prevents noise at a low range of frequencies, the silencer must be long, This is an obstacle to efforts to reduce the size of the vacuum pump device. The resonance type silencer can reduce the size but does not interfere with the flow of the gas to be discharged, so that noise can be prevented in a frequency range smaller than that of the expansion silencer.

The gas exhausted from the exhaust port of the vacuum pump is continuously passed through the at least two large chambers, the first throttle throat between the large chambers, and the second throat throat where the final one of the large chambers is exhausted to the atmosphere. So that the noise generated by the gas is reduced before it is discharged to the atmosphere (Japanese Patent Application Laid-Open No. 2001-289167 (Patent Document 1)). In the proposed silencer, the opening of the first throttling throat is adjusted to a wider set point or a smaller set point, depending on the pressure or velocity of the gas passing through the first throttling throttle.

When the gas is exhausted from the large-capacity chamber by using a multi-stage Roots dry vacuum pump, the gas flows at high speed inside thereof and is excessively compressed in the pump due to different exhaust velocities at the respective stages of the pump. In the pump, a compressive force is so high that a rotational speed control mode is triggered to lower the rotational speed of the pump in order to prevent the pump from operating under overload. As the rotational speed of the pump is lowered, the exhaust velocities in the pump also become lower, increasing the time required to evacuate gas from the chamber and consequently increasing the time required for semiconductor or liquid crystal device manufacturing equipment Leading to an increase in lead time. One solution to this problem is to use an excessive compression preventing mechanism comprising an intermediate release outlet port disposed at the middle end of the pump to discharge excessively compressed gas from the pump So as to prevent the gas from being excessively compressed in the pump.

The multi-stage dry vacuum pump apparatus generally includes a silencer disposed at the exhaust portion of the gas furnace and a check valve disposed downstream of the silencer.

The noise apparatus disclosed in Patent Document 1 is a vacuum pump which may be large or small in size, or may be operated in various manners, such as a vacuum pump, a vacuum pump, or the like in order to efficiently reduce the noise generated by the gas discharged from the exhaust port of the vacuum pump while minimizing the power loss of the vacuum pump. The opening of the first throttle throttle is adjusted to a wider set value or a narrower set value depending on the pressure or the velocity of the gas exhausted from the exhaust port of the vacuum pump operating under the conditions. Accordingly, the noise apparatus disclosed in Patent Document 1 can not effectively reduce noise at a wide range of frequencies from a low frequency to a high frequency generated when the gas is discharged from the vacuum pump, and is suitable for reducing the size of the silencer It is not a structure.

In the case where the gas is excessively compressed at the middle stage of the pump during the operation of the multistage direct dry vacuum pump, the rotational speed control mode is triggered so that the rotational speed of the pump is slowed down, . When the rotational speed of the pump is slowed down, the exhaust speed in the pump is also slowed down. According to one solution, as described above, in addition to the final outlet for finally discharging the gas from the pump, an intermediate release outlet for discharging the excessively compressed gas from the pump to discharge the excessively compressed gas And is disposed at the middle end of the pump. As a result, it becomes necessary to effectively prevent the noise of the gas discharged from the final outlet and the noise of the excessively compressed gas discharged from the intermediate release outlet. There has been a need for the development of a dry vacuum pump coupled with a silencer that meets these requirements. The conventional dry vacuum pump provided with the intermediate release outlet can not prevent the noise of the excessively compressed gas because the intermediate release outlet is disposed downstream of the silencing device.

In a multi-stage roots dry vacuum pump, the volume of the rotor chamber at the initial stage is generally determined by the exhaust velocity of the vacuum pump to be designed. Therefore, when the vacuum pump is designed for high exhaust speed, it is necessary to increase the volume of the rotor chamber at the initial stage. On the other hand, the volume of the rotor chamber in the final stage is reduced in order to reduce the heat (compression heat) to be produced by the pressure difference between the forward and backward pressures of the rotor chamber at said final stage, But also to reduce the power consumption of the motor that rotates the rotor. However, if the volume of the rotor chamber at the final stage is reduced, the gas can not be discharged smoothly. Since there is a trade-off relationship between the volume ratio and the exothermic heat, it is determined whether the volume ratio (compression ratio) should be increased or decreased depending on which of the volume ratio and the heat generation should be emphasized in designing the vacuum pumps. The position and the volume ratio (compression ratio) at which the overpressure prevention mechanism is installed are important for lowering the exhaust speed.

Conventional dry vacuum pumps have a silencer disposed at the exhaust portion and a check valve disposed downstream of the silencer independently of the silencer. Therefore, since the silencer and the check valve are disposed independently of each other in the exhaust part, in addition to the silencer and the check valve, parts for interconnecting the silencer and the check valve are required. Therefore, the number of parts used increases, making the size of dry vacuum pumps large. Therefore, the size of the dry vacuum pumps can not be reduced, and the manufacturing cost is high.

The multi-stage roots type dry vacuum pumps include a motor unit having a motor for operating the pump unit. Generally, the motor unit is integrally coupled to the pump unit by a flange. Therefore, the heat generated by the pump unit is transmitted to the motor casing through the flange. The temperature of the motor casing rises due to heat from the pump unit and also by heat generated by the motor itself. Until now, the motor casing is cooled by the coolant passing through the coolant passage formed in the outer circumferential region of the motor casing around the motor stator. Therefore, reducing the size of the multi-stage roots-type dry vacuum pumps has been prevented since the motor casing must be thick enough to accommodate the cooling fluid therein.

The pump unit also comprises mating surfaces each of which is held against each other and comprises separate upper and lower members joined together by a plurality of bolts arranged equidistantly in the axial direction, And a casing. The rotor casing is provided with gas flow paths at a plurality of stages formed therein to transfer compressed gas from each of the rotor chambers to a next one of the rotor chambers. The bolts coupling the separate upper and lower members together are equidistantly spaced axially about the rotor chambers to escape interference with the rotor chambers. Therefore, the thickness of the rotor casing becomes thick, which makes the width of the multi-stage roots dry vacuum pumps large and prevents their size from being reduced.

The present invention has been devised in view of the above situation. Therefore, a first object of the present invention is to provide a dry vacuum pump device comprising a single multi-stage constant-angle dry vacuum pump or a plurality of single-stage multi-stage constant-angle dry vacuum pumps, and a wide range of frequencies from low to high frequency The present invention provides a muffling device capable of reducing the size of a gas exhausted from a final outlet and an intermediate release outlet of the multi-stage constant-displacement dry vacuum pump or pumps.

It is a second object of the present invention to provide a multi-stage roots-type pump having an overpressure prevention mechanism disposed at a suitable position to prevent over-compression of the gas in the pump to prevent the pump rotational speed from being excessively reduced due to overload And to provide a dry vacuum pump device including a dry vacuum pump which shortens the time required for the pump to discharge the gas.

A third object of the present invention is to provide an exhaust unit which is made up of a small number of parts, is low in manufacturing cost, can be reduced in size, and can reduce noise.

It is a fourth object of the present invention to provide a silencer capable of effectively reducing noise and reducing its size in a wide range of frequencies from a low frequency to a high frequency.

The present invention relates to a multistage roots-type dry vacuum pump having a simplified cooling mechanism for cooling a motor of a multi-stage roots-type dry vacuum pump by blocking heat transmitted from the pump unit to a motor casing of the motor, It is also possible to provide the pump unit with a rotor casing made of separate vacuum pump devices of small size, including a pump, and separate members joined together by a specially designed structure of a small size pump unit have.

In order to achieve the first object, the present invention provides a multi-stage constant-displacement dry vacuum pump having a final outlet at the final stage for discharging gas and an intermediate release outlet at the intermediate stage for discharging the excessively compressed gas, An outlet check valve connected to said final outlet, said outlet check valve having an outlet, an intermediate check valve connected to said intermediate release outlet and having an outlet, an outlet of said outlet check valve and an outlet of said middle check valve And a silencer connected to the exhaust passage and to the exhaust passage and having an outlet connected to a final exhaust passage exhausted to the atmosphere.

The exhaust check valve, the intermediate check valve, the exhaust passage, and the silencer are preferably integrally coupled as an exhaust unit.

The multi-stage constant-displacement dry vacuum pump includes a five-stage dry vacuum pump, and the intermediate release outlet is connected to the second end of the five-stage dry vacuum pump.

Preferably, the silencing device includes a composite silencing device including a resonance type silencing device and an expansion type silencing device, wherein the resonance type silencing device is configured such that the gas is supplied to the upstream side of the silencing device And the inflatable silencer is disposed in a region downstream of the silencer with respect to a direction in which the gas passes through the silencer.

The multi-stage constant-displacement dry vacuum pump may include a single multi-stage constant-displacement dry vacuum pump or a plurality of multi-stage constant-angle dry vacuum pumps connected in series.

According to the dry vacuum pump apparatus, the exhaust check valve is connected to the final outlet of the multi-stage constant-displacement dry vacuum pump, the intermediate check valve is connected to the intermediate release outlet of the multi-stage constant-displacement dry vacuum pump, The exhaust passage is connected to the outlet of the exhaust check valve and to the outlet of the intermediate check valve, and the silencer has an outlet connected to the exhaust passage and connected to a final exhaust passage exhausted to the atmosphere. Therefore, the noise of the gas discharged from the final outlet and the noise of the excessively compressed gas discharged from the intermediate release outlet can be effectively prevented (reduced).

In order to achieve the second object, the present invention provides a multi-stage roots-type dry vacuum pump having a final outlet at the final stage for discharging gas and an intermediate release outlet at the intermediate stage for discharging the excessively compressed gas, An exhaust check valve connected to the final outlet and exhausted to the atmosphere and an intermediate check valve connected to the intermediate release outlet and exhausted to the atmosphere.

The multi-stage roots dry vacuum pump preferably comprises a five-stage roots-type dry vacuum pump comprising rotor chambers in five stages and rotors respectively disposed in the rotor chambers, Wherein the rotor disposed in the rotor chamber at the fifth stage is in communication with the rotor chamber at the second stage and has an axial width that is at least twice the axial width of the rotor disposed in the rotor chamber at the second end, .

Further comprising a silencer having an outlet connected to the outlet of the outlet check valve and an outlet of the intermediate check valve and an outlet connected to the exhaust line and connected to a final exhaust line exhausted into the atmosphere Do.

The exhaust check valve, the intermediate check valve, the exhaust passage, and the silencer are preferably integrally coupled as an exhaust unit.

The multi-stage roots dry vacuum pump includes a booster pump and a main pump, and the booster pump has a final outlet connected to an inlet of the main pump, and the exhaust unit is connected to the main pump.

According to the dry vacuum pump apparatus, the multistage roots-type dry vacuum pump has an intermediate release outlet at the intermediate stage for discharging excessively compressed gas, and the intermediate stage check valve is connected to the intermediate release outlet And is exhausted to the atmosphere. As a result, it is possible to prevent the dry vacuum pump from operating at a low rotational speed under an overload, thereby reducing the time required for discharging the compressed gas.

Preferably, the multi-stage roots-type dry vacuum pump comprises a five-stage roots-type dry vacuum pump, the intermediate check valve is connected to the rotor chamber at the second stage and is disposed in the rotor chamber at the first stage The rotor having an axial width that is at least twice the axial width of the rotor disposed in the rotor chamber at the second end. The intermediate check valve is connected to an intermediate release outlet which is connected to the rotor chamber at the second compression stage and is exhausted to the atmosphere. Therefore, it is possible to prevent the dry vacuum pump from operating at a low rotational speed under an overload, thereby reducing the time required for discharging the compressed gas.

An outlet of the exhaust check valve and an outlet of the middle check valve are connected to the exhaust passage, and the silencer is connected to the exhaust passage. The outlet of the silencer is connected to a final exhaust line connected to an exhaust vent to the atmosphere. Therefore, the noise of the gas discharged from the final outlet and the noise of the excessively compressed gas discharged from the intermediate release outlet can be effectively prevented (reduced).

Preferably, the exhaust check valve, the intermediate check valve, the exhaust passage, and the silencer are integrally coupled as the exhaust unit, and the number of parts of the exhaust system of the dry vacuum pump scales the exhaust system. down, so that the size of the dry vacuum pump device can be reduced and can be manufactured at low cost.

In order to achieve the third object, the present invention is connected to a multi-stage vacuum pump having a final outlet at the final stage for discharging the gas and an intermediate release outlet at the intermediate stage for discharging the excessively compressed gas And the exhaust unit. The exhaust unit includes an exhaust check valve connected to a final outlet of the multi-stage vacuum pump, an intermediate check valve connected to an intermediate release outlet of the multi-stage vacuum pump, And a silencer connected downstream of the check valve. The exhaust check valve, the intermediate check valve, and the silencer are integrally coupled to each other.

Since the exhaust unit check valve, the middle portion check valve, and the silencer connected downstream of the exhaust unit check valve and the middle portion check valve are integrally coupled to each other in the exhaust unit, , Can be reduced in size, and can be made inexpensively.

When the exhaust unit is simply installed in the multi-stage vacuum pump, the final outlet is connected to the exhaust check valve, and the intermediate release outlet is connected to the intermediate check valve, the multi-stage vacuum pump is connected to the exhaust check valve, It is combined with a silencer. As a result, they can be easily assembled into a dry vacuum pump unit, which reduces size and cost by reducing the size and cost of the exhaust unit.

In order to achieve the fourth object, the present invention provides a resonance type silencing device in which a gas is disposed in an upstream region with respect to a direction in which the gas passes through the silencing device, The present invention provides a silencer including an inflatable silencer. The resonance type silencer and the expansion silencer are integrally combined with each other.

The present invention also provides a silencing device comprising a lid and a thick plate type silencing device casing, wherein the silencing device casing serves as a resonance chamber serving as a resonance type silencing device and as an expansion type silencing device And a gas path formed on a side surface thereof and opened on the side surface. The resonance chamber is in communication with the gas path through a resonance opening and the expansion chamber is in communication with the gas path through a throttle throttle downstream of the resonance opening with respect to the direction in which the gas passes through the silencing device casing. The side surface of the silencer casing is covered with the lid to integrally join the resonant silencer and the silencer.

Since the resonance type silencer is disposed in the upstream region with respect to the direction in which the gas passes through the silencer, the expansion silencer is disposed in the downstream region with respect to the direction in which the gas passes through the silencer, The apparatus and the inflatable silencer are integrally coupled to each other, and the silencer can prevent (reduce) noise in a wide range of frequencies and reduce the size.

The silencing device casing of the compound silencing device may include a resonance chamber serving as a resonance type silencing device, an expansion chamber serving as an expansion type silencing device, and a gas path formed on the side surface thereof and opened from the side surface. Wherein the resonance chamber is in communication with a gas path through a resonance opening that opens at the side surface and the expansion chamber is connected to the gas path through a throttle slot in the downstream of the resonance opening with respect to a direction in which the gas passes through the silencing device casing . The side surface of the silencer casing is covered with the lid to integrally join the resonant silencer and the silencer. According to this configuration, the noise apparatus can prevent (reduce) noise in a wide range of frequencies and can reduce the size. The expansion chamber may be divided into a first expansion chamber and a second expansion chamber. The resonant chamber and the first expansion chamber may share a wall, and the first expansion chamber and the second expansion chamber may share a wall. This further reduces the size of the silencer.

The resonant silencer is disposed in an upstream region with respect to the direction in which the gas passes through the silencer and the inflatable silencer is disposed in the downstream region with respect to the direction through which the gas passes through the silencer. As a result, the silencing device is able to prevent noise of gas exiting the dry vacuum pump over a wide range of frequencies to maintain a silent environment around the dry vacuum pump device including the dry vacuum pump and silencer . Since the size of the silencer can be reduced, the dry vacuum pump unit can also be reduced in size.

The present invention relates to a rotor casing comprising a rotor casing, a pair of rotating shafts rotatably supported by the rotor casing, a pair of rotor sets in a plurality of stages fixedly mounted on the rotating shafts, A plurality of rotor chambers, the rotor sets including a pump unit disposed in the rotor chambers; A motor for rotating rotary shafts for transferring gas compressed by rotors in the rotor chambers continuously through the rotor chambers; And a flange that integrally couples the motor unit to the pump unit and includes a coolant passage for allowing the coolant to pass therethrough.

According to the dry vacuum pump apparatus, when the coolant passes through the coolant provided in the flange that connects the motor unit and the pump unit to each other, the heat transmitted from the pump unit to the motor casing is absorbed, And is prevented from being transmitted to the motor by the passing coolant. As a result, the motor casing does not need to have any cooling means for dissipating heat from the pump unit. Therefore, the width dimension of the motor casing is smaller than that of a conventional motor casing in which a cooling furnace may be formed.

The present invention relates to a rotor casing comprising a rotor casing, a pair of rotating shafts rotatably supported by the rotor casing, a pair of rotor sets in a plurality of stages fixedly mounted on the rotating shafts, Wherein the rotor sets are disposed in the rotor chambers, and the rotor casing comprises a plurality of gas passages; And a motor unit for rotating the rotary shafts for conveying gas compressed by the rotors in the rotor chambers in succession through the rotor chambers and the gas chambers. have. Wherein the rotor casing comprises a pair of separate members having respective mating surfaces held about one another and coupled to each other by a plurality of bolts arranged at axial intervals, Lt; RTI ID = 0.0 > and / or < / RTI > through the separate members in the gas free zones.

According to the dry vacuum pump apparatus, the separate members of the rotor casing are formed by bolts extending between the gas passages in proximity to the peripheral positions where the gas passages are formed and through the separate members in the gas passages free areas Respectively. As a result, the areas where the bolts extend through the separate members may become close to the inner circumferential surface of the rotor casing. Therefore, the width dimension of the rotor casing can be reduced, and the size of the pump unit can be reduced.

1 is a vertical sectional front view of a dry vacuum pump apparatus according to an embodiment of the present invention;
FIG. 2 is a sectional view taken along the line AA in FIG. 1; FIG.
FIG. 3 is a front view showing rotors and rotating shafts of a multi-stage roots-type dry vacuum pump provided in the dry vacuum pump apparatus shown in FIG. 1; FIG.
Figure 4 is a schematic view of the dry vacuum pump apparatus shown in Figure 1 showing the internal gas flow;
5 is a schematic view of the structure of an exhaust unit of the dry vacuum pump apparatus shown in FIG. 1;
FIG. 6A is a plan view showing a structure of an exhaust unit of the dry vacuum pump apparatus shown in FIG. 1; FIG.
Fig. 6B is a front view showing the structure of the exhaust unit of the dry vacuum pump apparatus shown in Fig. 1; Fig.
FIG. 7A is a side cross-sectional view showing the structure of the silencer of the exhaust unit of the dry vacuum pump apparatus shown in FIG. 1; FIG.
FIG. 7B is a sectional view taken along the line BB in FIG. 7A; FIG.
8 is a vertical sectional view of yet another vacuum pump apparatus;
FIG. 9 is a cross-sectional view taken along line CC of FIG. 8;
10 shows the positions of the bolt insertion holes for inserting the fastening bolts through the rotor casing of the multi-stage roots type dry vacuum pump provided in the dry vacuum pump device shown in FIG. 8, and also the positions of the bolt insertion holes according to the comparative example drawing; And
11 is a schematic view of a dry vacuum pump apparatus according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a vertical sectional front view of a dry vacuum pump apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line A-A of FIG. The dry vacuum pump apparatus includes a multi-stage roots type dry vacuum pump (hereinafter simply referred to as "dry vacuum pump") 10. The dry vacuum pump 10 is a five stage dry vacuum pump and includes two rotary shafts 11a and 11b which are rotatably supported by bearings 20 and 21 on opposite ends of the rotary shafts 11a and 11b Shaped rotors 12a, 12b, 12c, 12d, and 12e, respectively, which are fixedly mounted on the rotor 5a. The rotors 12a, 12b, 12c, 12d and 12e will also be referred to collectively as "rotors 12 ".

There are small gaps formed between the rotors 12 and between the rotors 12 and the inner circumferential surface of the rotor casing 14 in which the rotors 12 are rotatably housed and the rotation shafts 11a and 11b Are rotated about their own axes, the rotors 12 are rotated about the axes of the rotating shafts 11a, 11b without contacting each other. The rotor casing 14 forms rotor chambers 13a, 13b, 13c, 13d and 13e for housing the rotors 12a, 12b, 12c, 12d and 12e, respectively. The gas pumped by the dry vacuum pump 10 is transferred through the rotor chambers 13a, 13b, 13c, 13d and 13e. The rotor chambers 13a, 13b, 13c, 13d and 13e are arranged in a row along the rotating shafts 11a and 11b in the rotor casing 14. [ The rotor casing 14 has an upper surface covered with a cover member (not shown). The rotor casing 14 is formed on the upper surface thereof and has an inlet 17 communicating with the rotor chamber 13a at the first end. The rotor casing 14 also has an outlet side surface, the outlet side of which is covered by a first side casing 26 secured thereto. A bearing casing (23) for housing bearings (21) therein is fixed to the side of the first side casing (26) away from the rotor casing (14). The first side casing 26 communicates with the rotor chamber 13e at a final stage and has a final outlet 18 formed at a side thereof toward the rotor casing 14. [ The final outlet 18 discharges gas into the atmosphere through an exhaust unit check valve and a silencer, as described later.

As shown in FIG. 1, a motor (e.g., a brushless DC motor) 22 is disposed at one side of the bearings 20 away from the rotor casing 14. The motor 22 includes a motor rotor 22a fixed to one end of the rotating shafts 11a and 11b and a motor stator 22b disposed around the motor rotor 22a. The motor 22 is supplied with variable-frequency power from a power source such as an inverter device or the like (not shown), and the rotational speed including the soft starting mode of the dry vacuum pump 10 is controlled do. The motor 22 is housed in a motor casing 24. If the motor 22 is comprised of a brushless DC motor, the rotors 12 are simultaneously rotated in opposite directions by the brushless DC motor through the rotating shafts 11a, 11b. Specifically, the timing gears 29 held in mesh with each other are fixed to the respective ends of the rotating shafts 11a, 11b away from the motor 22. The bearings 21 as well as the timing gears 29 are housed in the bearing casing 23. The bearings 20 and 21 are held by respective bearing cases 40 and 41 accommodated in the motor casing 24 and the bearing casing 23, respectively.

In each of the rotor chambers 13a to 13e, a gas confined between the inner circumferential surface of the rotor casing 14 and the rotors 12 mounted on the rotating shafts 11a, 11b is supplied to the inlet of the rotor chamber To the outlet side. The rotor casing 14 includes inner and outer peripheral walls 15a, 15b, 15c, 15d and 15e formed around the respective rotor chambers 13a, 13b, 13c, 13d and 13e, And a double-walled casing. The outlet side of the rotor chamber 13a communicates with the inlet side of the rotor chamber 12b by the gas path 15a. Similarly, the outlet sides of the rotor chambers 13b, 13c, 13d and 13e are connected to the inlet of the rotor chambers 13c, 13d and 13e by respective gas passages 15b, 15c, 15d and 15e, Lt; RTI ID = 0.0 > 18 < / RTI > Therefore, gas compressed by the rotor 12a in the rotor chamber 13a is transferred from the outlet side of the rotor chamber 13a to the inlet side of the rotor chamber 13b through the gas path 15a. Therefore, the gas is continuously compressed in the rotor chambers 13a to 13e and is transferred to the final outlet 18 through the gas passages 15a to 15e.

Generally, in a multi-stage roots type dry vacuum pump, the volume of the rotor chamber at the initial stage is determined by the exhaust speed of the vacuum pump to be designed. Therefore, if the vacuum pump is designed for high exhaust speed, it is necessary to increase the volume of the rotor chamber at the initial stage. On the other hand, the volume of the rotor chamber in the final stage is reduced in order to reduce the heat (compression heat) to be produced by the pressure difference between the forward and backward pressures in the rotor chamber in the final stage, It needs to be reduced to reduce the power consumption of the motor that rotates the rotor. However, if the volume of the rotor chamber at the final stage is reduced, the gas can not be discharged smoothly. Since there is a trade-off between the volume ratio and the exothermic heat, it is determined whether the volume ratio (compression ratio) should be increased or decreased depending on whether the volume ratio and the exothermic heat should be emphasized in designing the vacuum pumps.

In the present embodiment, the axial width of the rotor chamber 13a at the first end is at least two times the axial width of the rotor chamber 13b at the second end. Specifically, as shown in Fig. 3, the axial width Wa of the rotor 12a at the first end is twice the axial width Wb of the rotor 12b at the second end, (Wa? 2Wb). The axial width Wc of the rotor 12c at the third stage, the axial width Wd of the rotor 12d at the fourth stage, and the axial width Wd of the rotor 12e at the final stage, (We) continues to decrease with predefined ratios. The axial widths of the rotor chambers 13a to 13e are substantially equal to the axial widths of the rotors 12a to 12e.

Further, in the present embodiment, the axial width Wa of the rotor 12a at the first end is set to 9 (i.e., the axial width Wa of the rotor 12e at the final stage) (Wa? 9We), the volume of the rotor chamber 13a in the first stage is at least nine times the volume of the rotor chamber 13e at the final stage. The ratio of the axial width Wa of the rotor 12a at the first end to the axial width We of the rotor 12e at the final end is determined by the rotor chamber 13a at the first end Which is equal to the volume ratio of the rotor chamber 13e at the final stage.

If the motor 22 is made up of a brushless DC motor, the rotational speed of the motor 22 may be adjusted so as to increase the exhaust speed while making the volume of the rotor chamber 13e at the final stage small. And may be controlled so as to reduce the heat generated by the motor 22 and the power consumed by the motor 22. [ In other words, the dry vacuum pump 10 achieves the same exhaust speed as conventional vacuum pumps employing conventional motors, has a larger volume ratio (compression ratio), generates less heat than conventional vacuum pumps . The brushless DC motor used as the motor 22 for rotating the two rotating shafts 11a and 11b is highly efficient and can handle large load fluctuations and has a large compressive force when the dry vacuum pump 10 is operated Can be generated.

The bearing 21 is disposed near the final outlet 18 of the dry vacuum pump 10. The rotating shafts 11a and 11b are rotatably supported by a bearing 20 and a bearing 21 located near the inlet 17. The bearing 21 is housed in the bearing casing 23 and the side casing 26 is disposed between the bearing casing 23 and the rotor casing 14. An unillustrated O-ring seal (sealing unit) is interposed between the bearing casing 23 and the side casing 26 to seal a small gap between the bearing casing 23 and the side casing 26 . (Not shown) is also interposed between the bearing casing 26 and the rotor casing 14 to seal a small gap between the side casing 26 and the rotor casing 14 . The bearing (20) is housed in the motor casing (24). Another side casing (30) is disposed between the motor casing (24) and the rotor casing (14). An unillustrated O-ring seal (sealing unit) is interposed between the side casing 30 and the rotor casing 14. (Sealing unit) not shown is also interposed between the side casing 30 and the motor casing 24. The O-

According to the dry vacuum pump having the above-described structure, when the motor 22 is activated to rotate the rotary shafts 11a and 11b, the rotors 12a, 12b, 12c, 12d, Is rotated to compress the aspirated gas from the inlet (17) in the openings (13a, 13b, 13c, 13d, 13e). The progressively compressed gas is continuously passed through the gas passages 15a to 15e to the final outlet 18 from which the compressed gas is connected to the final outlet 18, Lt; / RTI > The exhaust unit 50 discharges the gas to the atmosphere. The exhaust unit 50 comprises an exhaust check valve (final check valve) 51, a middle check valve 52, and a silencer 53. The outlet check valve 51 is connected to the final outlet 18 via a gas path 54. The intermediate check valve 52 is connected to the intermediate release outlet 19 (FIG. 4) formed in the rotor casing 14 and communicated with the second gas passage 15b through the gas passage 55 do. The intermediate release outlet 19 serves to discharge the compressed gas from the second gas path 15b to the atmosphere at a pressure level higher than atmospheric pressure in order to reduce the power loss of the dry vacuum pump 10 .

4 schematically shows an internal gas flow and an exhaust unit 50 and a dry vacuum pump 10 of the dry vacuum pump apparatus. 4, when the dry vacuum pump 10 is operating, the gas sucked into the inlet 17 flows through the gas passages 15a to 15e and the final outlet 18 to the exhaust unit (not shown) 50, then passes through the exhaust check valve (final check valve) 51 and the silencer 53, and is discharged to the atmosphere. For example, when the dry vacuum pump 10 is operated, if the gas is excessively compressed in the dry vacuum pump 10, the gas flows into the gas chamber 15b communicating with the rotor chamber 13b in the second stage From the intermediate release outlet 19 in communication with the exhaust unit 50. In the exhaust unit 50, the gas flows into the silencer 53 through the intermediate check valve (overpressure prevention check valve) 52. The exhaust check valve 51, the intermediate check valve 52, and the silencer 53 are integrally disposed in the exhaust unit 50, as described later. Therefore, when the exhaust unit 50 is installed on the dry vacuum pump 10, the exhaust part check valve 51, the middle part check valve 52, Is installed in the vacuum pump (10).

Fig. 5 schematically shows the structure of the exhaust unit 50. Fig. As described above, the dry vacuum pump 10 includes rotor chambers 13a, 13b, 13c, 13d and 13e. As shown in FIG. 1, the rotors 12a, 12b, 12c, 12d, and 12e are disposed in the rotor chambers 13a, 13b, 13c, 13d, and 13e, respectively. The gas discharged from the final outlet 18 which is compressed in the rotor chambers 13a to 13e of the dry vacuum pump 10 and communicated with the rotor chamber 13e at the final stage is supplied to the exhaust unit 50 Flows into the exhaust check valve (51) through the provided gas path (54). The gas flowing from the exhaust check valve 51 flows into the silencer 53 through the exhaust passage 56 provided in the exhaust unit 50. [ The intermediate release outlet 19 communicating with the second rotor chamber 13b of the dry vacuum pump 10 communicates with the intermediate check valve 52 through the gas path 55 provided in the exhaust unit 50 do. When the gas is excessively compressed in the dry vacuum pump 50, the excessively compressed gas flows into the silencer 53 through the intermediate check valve 52 and the exhaust passage 56.

Fig. 6A is a plan view showing the structure of the exhaust unit 50, and Fig. 6B is a front view showing the structure of the exhaust unit 50. Fig. As shown in FIGS. 6A and 6B, the exhaust unit 50 includes a valve unit 50a and a silencer unit 50b. The valve portion 50a houses the exhaust portion check valve 51 and the intermediate portion check valve 52 therein. 4 and 5, the exhaust check valve 51 has an inlet communicating with the final outlet 18 through the gas path 54. [ The intermediate check valve (52) has an inlet communicating with the intermediate release outlet (19) through the gas path (55). The exhaust part check valve 51 and the intermediate part check valve 52 are provided with respective outlets communicating with the exhaust path 56 communicating with the gas path 61 formed in the silencer part 50b It is. The silencer unit 50b housing the silencer 53 therein has a final exhaust path 56a formed therein and extending downstream from the outlet of the silencer 53. [ The final exhaust passage 56a is connected to the exhaust port 58 of the apparatus which is exhausted to the atmosphere, as shown in Fig.

The gas passing through the exhaust check valve 51 and the intermediate check valve 52 flows into the silencer 53. After the noise of the gas is reduced by the silencer 53, the gas is discharged from the exhaust unit 50. FIG. 7A is a side sectional view showing the structure of the silencer 53 in the silencer unit 50b, and FIG. 7B is a sectional view taken along the line B-B in FIG. 7A. 7A and 7B, the silencing device 53 includes a composite silencing device including a resonance type silencing device 53-1 and an expansion type silencing device 53-2 that are integrally coupled to each other . A wall 70 is interposed between the resonance type silencer 53-1 and the expansion silencer 53-2. The resonance type silencer 53-1 and the expansion silencer 53-2 communicate with the gas path 61 communicating with the exhaust path 56. [ The resonance type silencer 53-1 is arranged upstream of the expansion silencer 53-2 with respect to the direction in which the gas passes through the silencer 53. [ In other words, the resonance type silencer 53-1 is disposed in the upstream region of the silencer unit 50b with respect to the direction in which the gas passes through the silencer 53, and the expansion silencer 53- 2 is disposed in a region downstream of the silencer unit 50b with respect to a direction in which the gas passes through the silencer 53. [

The silencer (53) includes a silencer (60) and a lid (69) in the form of a thick plate. The muffler casing (60) includes a groove-like gas passage (61) formed on a side surface thereof and opened outward from the side surface and communicating with the exhaust passage (56) A concave resonance chamber 62 serving as the first expansion chamber 53-1 and a concave first expansion chamber 63 opening outwardly from the side surface and acting as the expansion silencer 53-2, And an expansion chamber (64). The muffler casing (60) further includes a groove-like resonance opening (65) that opens outwardly from the side and communicates the resonance chamber (62) with the gas path (61) A first groove throttle slot 66 communicating the chamber 63 with the gas path 61 and a second throttle throat 66 communicating the first expansion chamber 63 with the second expansion chamber 64 67), and a third throttle throttle (68) for communicating the second expansion chamber (64) with the external space.

The side surface of the muffler casing 60 in which the gas passage 61, the resonance chamber 62, the first expansion chamber 63 and the second expansion chamber 64 are formed is connected to the gas passage 61 ), The resonance chamber 62, the first expansion chamber 63, and the lid 69 that closes the open sides of the second expansion chamber 64. The resonance chamber 62 and the first expansion chamber 63 communicate with the gas path 61 through the resonance opening 65 and the first throttle throttle 66, respectively. The first expansion chamber (63) and the second expansion chamber (64) communicate with each other through the second throttle throttle (67). And the second expansion chamber 64 is exhausted to the atmosphere through the third throttle throttle 68. [

As described above, the silencer 53 includes a resonant silencer 53-1 having openings closed by the lid 69 and housed in a silencer casing 60 in the form of a thick plate, And a complex silencer including an expandable silencer (53-2). The silencer (53) is made of the lead (69) and the silencer casing (60) in the form of a thick plate in the present situation, so that the shape is flat and the size is reduced. The noise of the gas flowing into the gas path 61 in the silencer unit 50b from the exhaust path 56 in the valve unit 50a flows into the resonance chamber 65 and the resonance chamber 62 (Reduced) by the natural frequency of the resonance type silencer 53-1. Then, the gas flows into the first expansion chamber 63 through the first throttle throttle 66, and the gas expands to have its prevented (reduced) noise. Thereafter, the gas flows into the second expansion chamber 64 through the second throttle throat 67, and the gas expands to have its prevented (reduced) noise. The gas then flows out of the silencer 50 and into the atmosphere through the third throttling throat 68, but the gas expands to have its prevented (reduced) noise.

The resonance type silencer 53-1 is advantageous in that its size can be reduced and it does not interfere with the flow of the gas through the gas path 61. [ However, the range of the frequencies of the noise that can be blocked by the resonance type silencer 53-1 is relatively narrower than that of the expansion type silencer. On the other hand, the inflatable silencer 53-2 can prevent noise at a wide range of frequencies. However, since the range of frequencies that can be blocked by the inflatable silencer 53-2 is inversely proportional to its length, the inflatable silencer 53-2 must be able to prevent noise at lower ranges of frequencies The length is increased. According to the present embodiment, the resonance type silencer 53-1 capable of reducing the size is used to prevent the noise of the gas at a low range of frequencies, and the length of the expansion Type noise silencer 53-2 is used to prevent noise of the gas at the remaining high range frequencies. Therefore, it is possible to reduce the size of both the resonance type silencing device 53-1 and the expansion type silencing device 53-2, thereby reducing the overall size of the silencing device 53, Noise can be prevented (reduced).

The resonance type silencer 53-1 does not interfere with the flow of the gas flowing into the gas path 61. Since the resonance silencing device 53-1 is located at the upstream portion of the gas path 61 even if the compound silencing device 53 is disposed at the discharge port of the gas exhaust path of the exhaust unit 50, The reduction of any gas discharge capability of the fuel cell stack 50 can be minimized.

The valve unit 50a and the silencer unit 50b of the exhaust unit 50 are integrally coupled to each other and constitute one component of the dry vacuum pump apparatus. As a result, the exhaust unit 50 is connected to the final outlet 18 of the dry vacuum pump 10 with pipes, which may be necessary to connect the exhaust check valve 51, (61) in the silencer section (50b), which may be necessary to connect the intermediate check valve (52) to the intermediate release outlet (19) It is not necessary to have components including fittings and fittings which may be required to connect to the exhaust path 56 in the first and second exhaust ports 50a, 50a. Thus, the exhaust unit 50 is manufactured with a reduced number of parts, and can be manufactured at low cost.

As described above, the exhaust check valve 51 is connected to the final outlet 18 of the dry vacuum pump 10, and the intermediate check valve 52 is connected to the middle release valve 18 of the dry vacuum pump 10, And is connected to the outlet 19. The outlet of the exhaust check valve 51 and the outlet of the intermediate check valve 52 are connected to the exhaust passage 56 and the silencer 53 is connected to the exhaust passage 56. The final exhaust passage 56a extends downstream from the silencer 53 and is exhausted to the atmosphere. With this structure, noise of the gas discharged from the final outlet 18 and noise of the excessively compressed gas discharged from the intermediate release outlet 19 can be effectively prevented (reduced).

The intermediate release outlet 19 is provided at an intermediate end of the dry vacuum pump 10 having a relatively high compression ratio and the intermediate check valve 52 is provided at an intermediate release outlet for exhausting the excessively compressed gas to the atmosphere. (19). As a result, the dry vacuum pump 10 is prevented from operating at a low rotational speed under an overload, thereby reducing the time required to discharge the compressed gas.

In the exhaust unit 50, the exhaust part check valve 51 and the intermediate part check valve 52 in the valve part 50a are connected to the exhaust part check valve 51 and the intermediate part check valve 51, And the silencer (53) disposed downstream of the silencer (52). Accordingly, the exhaust unit 50 is manufactured with a small number of parts, and its size is made small.

The resonance type silencer 53-1 is disposed in an upstream region of the silencer unit 50b with respect to a direction in which the gas passes through the silencer 53 and the expansion silencer 53-2 , And the gas is disposed in a region downstream of the silencer unit 50b with respect to a direction through which the silencer 53 passes. The resonance type silencer (53-1) and the expansion silencer (53-2) are integrally coupled to each other. Therefore, the silencing device 53 can prevent noise at a wide range of frequencies and can reduce the size. By using the silencer 53 as a silencer combined with a dry vacuum pump, the size of the silencer unit including the silencer can be reduced, and a dry vacuum pump capable of preventing noise at a wide range of frequencies Can be made small.

Fig. 8 is a vertical cross-sectional view of another dry vacuum pump apparatus, and Fig. 9 is a cross-sectional view taken along line C-C of Fig. The components of the dry vacuum pump apparatus shown in Figs. 8 and 9, which correspond to or correspond to those of the dry vacuum pump apparatus shown in Figs. 1 to 7, are denoted by the same or corresponding reference numerals, do.

The dry vacuum pump apparatus of the present embodiment includes a multi-stage roots type dry vacuum pump (hereinafter simply referred to as "dry vacuum pump") including a pump unit P and a motor unit M. The pump unit P of the dry vacuum pump includes a fifth-stage pump, and the motor unit M includes a motor (e.g., a brushless DC motor) 8, gas passages 15a, 15b, 15c and 15d are formed between the outer peripheral wall and the inner peripheral walls of the double walled rotor casing 14, and the gas passage 15e is omitted from the illustration. This omission also applies to Fig. 10, which will be described later.

According to the dry vacuum pump, the motor unit M is connected to a motor casing (not shown) coupled to the side casing 30 of the pump unit P by a flange 31 provided on a side surface of the motor casing 24 incorporated in the pump unit P. [ (24). In other words, the motor unit M and the pump unit P are integrally joined to each other by the flange 31. The gas compressed by the continuous rotors 12 in the pump unit P is continuously transferred to the outlet side through the gas passages 15a to 15d. As the gas is compressed by the rotors 12, the rotor casing 14 of the pump unit P, the side casing 30, and the flange 31 to which the motor unit M is attached, As shown in FIG. The compressed heat is also transferred to the bearing casing (23) through the side casing (26) of the pump unit (P).

The compression heat generated by the gas compressed by the pump unit P is transmitted to the motor casing 24 of the motor unit M as described above. Therefore, the temperature of the motor casing 24 rises, adversely affecting the characteristics of the motor 22 housed in the motor casing 24. In this embodiment, in order to prevent the characteristics of the motor 22 from being adversely affected by the heat, a cooling pipe 32 is embedded in the flange 31, and a coolant such as cooling water is supplied to the cooling pipe 32 To absorb and block the heat transmitted from the rotor casing 14 of the pump unit P to the motor casing 24 of the motor unit M. [ The motor casing 24 of the motor unit M does not need to have any cooling means for dissipating heat transmitted from the pump unit P. [ Heat generated by the motor casing 24 itself is radiated from the motor casing 24 naturally. Instead of embedding the cooling pipe 32 in the flange 31, a coolant may be directly formed in the flange 31. [

Until now, a cooling pipe for flowing the coolant from the motor casing 24 is buried in order to prevent the temperature of the motor casing 24 from rising due to heat transmitted from the pump unit P to the motor casing 24 It was very common to do. Therefore, the wall thickness of the motor casing 24 must be thick, which hinders the attempt to reduce the size of the motor casing 24. According to the present embodiment, the cooling pipe 32 is fixed to the pump unit P and embedded in the relatively thick flange 31. According to the cooling pipe 32 embedded in the flange 31, the motor casing 24 need not have any cooling means, so that the motor casing 24 can control the weight and size of the motor unit M The wall thickness can also be reduced to reduce it.

9, the pump unit P has respective mating surfaces held against each other, and has separate upper and lower members 14-1, 14-2 coupled to each other by a plurality of bolts 34, 14-2). As shown by the dotted lines in FIG. 10 showing only the lower member 14'-2, the conventional rotor casing 14 'has a larger wall thickness than the other members 14-1 and 14-2 of this embodiment and a plurality of (in FIG. 10, four on each side in FIG. 10) extending through the bolt insertion holes formed in the peripheral regions of the gas passages 15a to 15d in the separate members 14'-1 and 14'- (14'-1, 14'-2) fastened together by bolts (34). Although the separate member 14'-1 is not illustrated in FIG. 10, each bolt 14'-1 formed in the separate member 14'-1 at the same positions as the separate member 14'- Bolts 34 are extended through the insertion ports. As a result, according to the conventional rotor casing 14 ', the wall thicknesses of the separate members 14'-1 and 14'-2 are different from those of the separate members 14-1 and 14-2 of the present embodiment It is thicker than wall thickness by wall thickness Δd.

According to the present embodiment, the dry vacuum pump apparatus has its reduced compressive force and its increased motor efficiency, thereby reducing power consumption. The dry vacuum pump included in the dry vacuum pump device is a multi-stage roots-type dry vacuum pump that compresses gas through continuous stages from a vacuum to the atmosphere to discharge the compressed gas. The dry vacuum pump optimizes the compression ratios at each of the stages to reduce power consumption through the reduced compression force. In order to optimize the compression ratios at each of the stages, the dry vacuum pump sets the rotational speed to maintain the desired exhaust speed and to minimize the mechanical losses accordingly. In order to reduce power consumption, it is effective to employ a brushless DC motor. Furthermore, according to the present embodiment, the motor efficiency is increased by changing the material of the iron core of the motor and improving the winding of the motor.

According to this embodiment, as described above, the compression ratios of the dry vacuum pump are optimized, and the heat generated by the pump is reduced. Therefore, it is possible to reduce the wall thickness of the rotor casing 14 by changing the positions where the bolts 34 are disposed to engage with the separate members 14-1 and 14-2. Furthermore, the dry vacuum pump has its rotational speed set to reduce the mechanical loss caused by the above for the optimization of the compression ratios at the respective stages of the dry vacuum pump. The rotational speed thus set causes the material of the iron core of the motor to be changed, and also the winding of the motor is improved, thereby increasing the motor efficiency. Therefore, the amount of heat generated by the motor 22 is reduced, and the heat generated by the motor 22 can be dissipated only by the coolant passing through the cooling pipe 31 embedded in the flange 31 do.

10, the bolt insertion ports for inserting the bolts 34 are inserted between the gas passages 15a and 15b and between the gas passages 15b and 15c, Are formed in the separate members (14-1, 14-2) between the gas passages (15c, 15d) in regions free of the gas passages (15a to 15d), and the gas passages (15a to 15d) Is formed on one side of the gas passage (15a) away from the gas passage (15b) close to peripheral positions to be formed. The bolts 34 are inserted through the respective bolt insertion openings to fasten the separate members 14-1 and 14-2 to each other. The bolt insertion ports are located closer to the inner circumferential surface of the rotor casing 14 than those indicated by dotted lines in FIG. 10, in the conventional rotor casing 14 '. Therefore, the separate members 14-1 and 14-2 of the rotor casing 14 may have a reduced wall thickness in the width direction of the rotor casing 14, thereby reducing the width dimension of the dry vacuum pump 14 Thereby reducing the size of the dry vacuum pump device.

The bearing casing 23 of the pump unit P includes timing gears 29 and bearings (e.g., combined angular ball bearings) 21 that generate heat due to mechanical losses when the dry vacuum pump apparatus is operating, Is housed therein. In order to reduce the temperature rise of the dry vacuum pump apparatus due to the heat generated by the mechanical loss, the cooling pipe 33 is embedded in the bearing casing 23 for the coolant so that the coolant supplied by the coolant pipe 33 . Instead of embedding the cooling pipe 33 in the bearing casing 23, a coolant passage may be formed directly in the bearing casing 23. [

As described above, the cooling pipe 32 is embedded in the flange 31 to which the motor unit M is coupled to the pump unit P. [ When the coolant passes through the cooling pipe 32, the heat transmitted from the pump unit P to the motor casing 24 is absorbed, and the coolant flowing in the cooling pipe 32 is supplied to the motor 22 And is blocked against being transmitted. The heat generated by the motor 22 is radiated from the motor casing 24 naturally. As a result, the motor casing 24 does not need to have any cooling means for dissipating heat from the pump unit P. Therefore, the width dimension of the motor casing 24 becomes smaller than that of the conventional motor casing in which the cooling furnace may be formed. Therefore, the size and weight of the motor unit M of the dry vacuum pump apparatus can be reduced.

11 is a schematic view of a dry vacuum pump apparatus according to another embodiment of the present invention. As shown in Fig. 11, the dry vacuum pump apparatus includes a main pump unit MP including a multi-stage roots type dry vacuum pump 10-2 and a multi-stage roots type dry vacuum pump 10-1. And a booster pump BP. The main pump MP has an inlet 17 connected to a final outlet 18 of the booster pump BP. The main pump MP is connected to an exhaust unit 50 including an exhaust part check valve 51, a middle part check valve 52 and a silencer 53. The main pump MP includes a final outlet 18 connected to the outlet check valve 51 and an intermediate release outlet 19 connected to the intermediate check valve 52.

In the illustrated embodiments, the silencer 53 comprises a composite silencer comprising a resonant silencer 53-1 and an expandable silencer 53-2. However, the silencer 53 may be any silencer effective to prevent noise of the excessively compressed gas discharged from the intermediate release outlet 19 and noise of gas exhausted from the final outlet 18. [ It is possible. Alternatively, the intermediate release outlet 19 and the final outlet 18 may each be connected to different silencers.

The dry vacuum pump of the dry vacuum pump apparatus is not limited to the Roots-type positive side dry vacuum pump, and may be various other dry vacuum pumps.

While certain preferred embodiments of the present invention have been shown and described in detail, it should be apparent that various changes and modifications can be made therein without departing from the scope of the appended claims.

Claims (13)

As a dry vacuum pump apparatus,
A positive-displacement dry vacuum pump having a final outlet at the final stage for discharging gas and an intermediate release outlet at the intermediate stage for discharging the excessively compressed gas;
An outlet check valve coupled to the final outlet, the outlet check valve having an outlet and configured to flow the gas discharged from the last stage;
An intermediate check valve coupled to the intermediate release outlet, the intermediate check valve having an outlet and configured to discharge the over-compressed gas;
An exhaust passage connected to an outlet of the exhaust portion check valve and an outlet of the middle portion check valve; And
And a silencer connected to the exhaust passage and having an outlet connected to a final exhaust path exhausted to the atmosphere. The method according to claim 1,
Wherein the exhaust check valve, the intermediate check valve, the exhaust passage, and the silencer are integrally coupled as an exhaust unit. The method according to claim 1,
Wherein the multi-stage constant-displacement dry vacuum pump comprises a five-stage dry vacuum pump and the intermediate release outlet is connected to a second end of the five-stage dry vacuum pump. The method according to claim 1,
The silencing device comprises a composite silencing device including a resonance type silencing device and an expanding silencing device, wherein the resonance type silencing device is arranged in the upstream region of the silencing device with respect to the direction in which the gas passes through the silencing device And wherein the inflatable silencer is disposed in a downstream region of the silencer with respect to a direction through which the gas passes through the silencer. The method according to claim 1,
Wherein the multi-stage constant-displacement dry vacuum pump comprises a single multi-stage constant-displacement dry vacuum pump or a plurality of multi-stage constant-displacement dry vacuum pumps connected in series. As a dry vacuum pump apparatus,
A multi-stage roots-type dry vacuum pump having a final outlet at the final stage to discharge the gas and an intermediate release outlet at the intermediate stage for discharging the excessively compressed gas;
An exhaust check valve connected to the final outlet, the exhaust check valve being configured to exhaust gas discharged into the atmosphere and discharged from the final stage; And
And an intermediate check valve connected to the intermediate release outlet and configured to vent to the atmosphere and to release the excessively compressed gas. The method according to claim 6,
Wherein the multi-stage roots dry vacuum pump comprises a five stage roots dry vacuum pump comprising rotor chambers in five stages and rotors respectively disposed in the rotor chambers,
The middle check valve communicates with the rotor chamber at the second end,
Wherein the rotor disposed in the rotor chamber in the first stage has an axial width that is at least twice the axial width of the rotor disposed in the rotor chamber in the second stage. The method according to claim 6,
An exhaust passage connected to an outlet of the exhaust portion check valve and an outlet of the middle portion check valve; And
And a silencer connected to the exhaust passage and having an outlet connected to a final exhaust path exhausted to the atmosphere. 9. The method of claim 8,
Wherein the exhaust check valve, the intermediate check valve, the exhaust passage, and the silencer are integrally coupled as an exhaust unit. 10. The method of claim 9,
Wherein the multi-stage roots dry vacuum pump comprises a booster pump and a main pump, the booster pump having a final outlet connected to an inlet of the main pump, the exhaust unit comprising a dry vacuum pump device . An exhaust unit connected to a multi-stage vacuum pump having a final outlet at the final stage for discharging the gas and an intermediate release outlet at the intermediate stage for discharging the excessively compressed gas,
An exhaust check valve adapted to be connected to a final outlet of the multi-stage vacuum pump, the exhaust check valve configured to flow gas discharged from the final stage;
An intermediate check valve adapted to be connected to the intermediate release outlet of the multi-stage vacuum pump and configured to release the excessively compressed gas; And
And a silencer connected downstream of the outlet check valve and the middle check valve,
Wherein the exhaust check valve, the intermediate check valve, and the silencer are integrally coupled to each other. A composite silencer for use in a vacuum pump,
The composite type silencing device includes a resonance type silencing device and an expansion type silencing device which are integrally coupled to each other, wherein the resonance type silencing device has a structure in which the exhaust gas from the vacuum pump passes through the silencing device Wherein the inflatable silencer is disposed in a downstream region of the silencer with respect to a direction through which the exhaust gas from the vacuum pump passes through the silencer,
Wherein the resonance type silencer includes a resonance chamber communicating with an exhaust passage through a resonance opening,
Wherein the expansion type silencing device comprises a first expansion chamber and a second expansion chamber, the first expansion chamber communicating with the exhaust passage via a first throttle throttle, and the second expansion chamber communicating with the second expansion chamber via a second throttle throttle, The second expansion chamber communicating with the first expansion chamber, and the second expansion chamber being exhausted to the atmosphere through a third throttling throttle,
Wherein a size of the first expansion chamber and the second expansion chamber in the vertical direction is different from each other. As a noise device,
Lid; And
The silencing device casing includes a resonance chamber serving as a resonance type silencing device, an expansion chamber serving as an expansion type silencing device, and an expansion chamber formed on the side surface thereof and opened on the side surface thereof A gas furnace,
Wherein the resonance chamber is in communication with the gas path through a resonance opening and the expansion chamber is in communication with the gas path through a throttle throttle downstream of the resonance opening with respect to a direction in which gas passes through the silencing device casing,
Wherein the side surface of the silencer casing is covered with the reed so that the resonant silencer and the inflatable silencer are integrally joined to each other.

Images