TWI518245B - Dry vacuum pump apparatus, exhaust unit, and silencer - Google Patents

Description

Dry vacuum pump unit, exhaust unit, and silencer

The present invention relates to a dry vacuum pump apparatus including a multistage positive-displacement dry vacuum pump (for example, a multi-stage root-type dry vacuum pump or the like), an exhaust unit, And a silencer. The multi-stage positive displacement dry vacuum pump is designed to reduce the noise of the dry vacuum pump exhaust gas, and the exhaust unit is disposed in the exhaust section of the multi-stage positive displacement dry vacuum pump, and the muffler is combined with the dry The vacuum pump is used to reduce the noise when the dry vacuum pump discharges gas. The silencer is small in size and can attenuate noise over a wide range of frequencies.

In recent years, dry vacuum pumping devices that can be easily operated under atmospheric pressure to create a vacuum environment have been used in a wide range of applications including semiconductor manufacturing equipment. In particular, semiconductor devices are produced by processes that include more than three hundred steps, and many vacuum pumps are used in the process. Therefore, it is very important to reduce the footprint of the vacuum pumping device in order to effectively utilize the floor area of the manufacturing plant. In particular, since a plurality of dry vacuum pump units are installed side by side in many applications, it is important to try to reduce the width of the dry vacuum pump unit. Since the vacuum pump is sometimes installed in a semiconductor manufacturing apparatus, it is important to reduce the size of the vacuum pump in order to reduce the line resistance between the vacuum pump and the semiconductor manufacturing apparatus.

The dry vacuum pump unit generates noise when exhausting gas, and in order to reduce noise, a muffler must be added to the exhaust section of the vacuum pump. There are two types of silencers on the market, namely expansion type and resonance. The inflated silencer is capable of muffling (reducing) noise over a wide range of frequencies, but the frequency that can be silenced by the inflated silencer is inversely proportional to the length of the silencer, so if the expander is to be silenced in the low frequency range Noise, the silencer needs to be long, but this hinders efforts to reduce the volume of the dry vacuum pump unit. Although the resonant muffler can reduce the volume without hindering the flow of gas, it can only silence noise that is less than the frequency that the expansion muffler can achieve.

There has been proposed a muffler in which a gas system discharged from a discharge port of a vacuum pump causes continuous flow through two or more large gas chambers, and a first throttle neck between the gas chambers (first The throttle throat) and the second throttle neck, through which the last air chamber can pass to the atmosphere, so that the noise generated by the gas can be reduced before the gas is discharged into the atmosphere (refer to Japanese invention Early Publication No. 2001-289167 (Patent Document 1)). In such a proposed silencer, the opening of the first throttle neck can be adjusted to a wider setting or a narrower setting depending on the gas pressure or flow rate through the first throttle neck.

When gas is discharged from the large volume chamber by using a multi-stage Roots type dry vacuum pump, the gas flows at a high rate therein, and is hierarchically compressed in the vacuum pump due to different discharge speeds of the stages. The compression power in the vacuum pump becomes very high, so that the speed control mode is activated to reduce the speed of the vacuum pump and to prevent the vacuum pump from operating under overload. When the speed of the vacuum pump is reduced, the exhaust speed of the vacuum pump is also reduced, resulting in an increase in the time required to discharge the gas out of the chamber, thereby increasing the capacity of the semiconductor or liquid crystal device production equipment combined with the multi-stage Roots type dry vacuum pump. Lead time increase plus. The solution to this problem is to provide an excessive compression preventing mechanism that includes an intermediate pressure relief outlet placed in the middle stage of the vacuum pump to discharge the supercompressed gas from the vacuum pump to avoid gas at The vacuum pump is super-compressed.

Multi-stage dry vacuum pumping devices typically include a muffler disposed in the exhaust section of the gas passage and a check valve disposed downstream of the muffler.

In the muffler disclosed in Patent Document 1, the opening of the first throttle neck can be adjusted to a wider setting or a narrower setting according to the gas pressure or flow rate of the exhaust gas from the exhaust port of the vacuum pump. Operating under various operating conditions, or the vacuum pump is of a large volume or a small volume, thereby effectively reducing the noise generated by the exhaust gas from the exhaust port of the vacuum pump, and also minimizing the power loss of the vacuum pump. However, the muffler disclosed in Patent Document 1 cannot effectively reduce the noise of the gas discharged from the low to high wide frequency range of the vacuum pump when the gas is discharged from the vacuum pump, and is not suitable for a structure for reducing the size of the muffler.

During operation, when the gas is overpressured in the intermediate stage of the dry vacuum pump, the speed control mode is activated to reduce the speed of the vacuum pump and to prevent the vacuum pump from operating under overload. When the speed of the vacuum pump is lowered, the exhaust speed of the vacuum pump is also lowered. According to the above solution, in addition to the final outlet to finally discharge the gas from the vacuum pump, an intermediate pressure relief outlet capable of discharging the super-compressed gas is disposed at an intermediate stage of the vacuum pump to discharge the overpressure gas out of the vacuum pump. As a result, it is necessary to effectively discharge the gas noise discharged from the final outlet and to discharge from the intermediate pressure relief outlet. The gas noise is silenced. There is a need to develop a dry vacuum pump in combination with a silencer to meet these requirements. A conventional dry vacuum pump provided with an intermediate pressure relief outlet cannot mute the noise of the supercompressed gas because the intermediate pressure relief outlet is disposed downstream of the muffler.

In a multi-stage Roots type dry vacuum pump, the capacity of the rotor chamber in the initial stage is determined by the discharge speed of the designed vacuum pump. Therefore, if the vacuum pump system is designed to have a high discharge speed, it is necessary to increase the rotor chamber capacity in the initial stage. On the other hand, the capacity of the rotor chamber in the final stage needs to be reduced, the heat generated by the pressure difference before and after the rotor chamber in the final stage (compression heat) is reduced, and the motor that drives the rotor is also reduced against the pressure difference. The energy of loss. However, if the capacity of the rotor chamber in the final stage is reduced, the gas cannot be smoothly discharged. Since there is a trade-off relationship between the volume ratio and heat generation, it is determined whether the volume ratio (compression ratio) is increased or decreased depending on whether the volume ratio or heat is generated when designing the vacuum pump. Stressed. The volume ratio (compression ratio) and the position at which the over-compression mechanism is prevented from being set are important for reducing the discharge speed.

The conventional dry vacuum pump has a muffler disposed in its exhaust section, and a check valve disposed downstream of the muffler and independent of the muffler, and since the muffler and the check valve are independently disposed in the exhaust section, there is a need In addition to the silencer and the check valve, an element for interconnecting the muffler and the check valve is provided. Therefore, the number of components is increased, making the dry vacuum pump larger. Dry vacuum pumps cannot be reduced in size and are expensive.

A multi-stage Roots type dry vacuum pump includes a motor unit having a motor to activate the pump unit. In general, the motor unit and the pump unit are flanged And they are integrally connected to each other. Therefore, the heat generated by the pump unit is transmitted to the motor housing via the flange. The temperature rise of the motor housing is due to the heat generated by the pump unit and the heat generated by the motor itself. Until then, the motor housing is cooled by the coolant flowing through the coolant passage, which is defined in the outer peripheral region of the motor housing surrounding the motor stator. Therefore, the motor housing needs to have a sufficient thickness to accommodate the coolant passage therein, but this prevents the reduced volume of the multi-stage Roots type dry vacuum pump.

The pump unit has a rotor housing that generally includes individual upper and lower elements, each of which has a mating surface that is fixed and locked to each other by a plurality of axially equidistantly disposed bolts. The rotor housing defines a plurality of stages of gas flow passages therein for conveying compressed gas within each rotor chamber to the next rotor chamber. The bolts that connect the individual upper and lower elements together are arranged around the rotor chambers in an axially equidistant manner so as not to interfere with the rotor chambers. However, the rotor housing has a large thickness, which makes the multi-stage Roots type dry vacuum pump have a large width and cannot reduce the volume.

In order to solve the above situation, a first object of the present invention is to provide a dry vacuum pump apparatus comprising a single multi-stage positive displacement Roots type dry vacuum pump or a plurality of series multistage positive displacement Roots type dry vacuum pumps and silencer The volume can be reduced to effectively reduce the gas discharged from the final outlet of the multi-stage positive displacement Roots dry vacuum pump or the plurality of multi-stage positive displacement Roots dry vacuum pumps and the intermediate pressure relief outlet. Noise in a wide range of frequencies.

A second object of the present invention is to provide a dry vacuum pump apparatus comprising a multi-stage Roots type dry vacuum pump having an over-compression preventing mechanism for preventing gas from being super-compressed in a vacuum pump, and preventing the rotation speed of the vacuum pump from being overloaded Slow, and can shorten the time required for the vacuum pump to discharge the gas.

A third object of the present invention is to provide an exhaust unit which is composed of a small number of edge members, which is low in manufacturing cost, can be reduced in volume, and can reduce noise.

A fourth object of the present invention is to provide a muffler that can be reduced in size to effectively reduce noise in a wide range from low frequency to high frequency.

The invention provides a dry vacuum pump device, which is small in size, and comprises a multi-stage Roots type dry vacuum pump, which has a simplified cooling mechanism for cooling a motor of a multi-stage Roots type dry vacuum pump, which is generated by a pump unit of a vacuum pump. The heat is blocked so that it is not transmitted to the motor housing of the motor, so that the volume of the motor can be small, and the pump unit has a rotor housing which is combined with each other by specially designed individual components, so that the pump unit is small in size .

In order to achieve the above first object, the present invention provides a dry vacuum pump apparatus comprising a multi-stage positive displacement dry vacuum pump having a final outlet for discharging gas at a final stage and a middle release for discharging super-compressed gas at an intermediate stage. a pressure outlet, an exhaust section check valve connected to the final outlet and having an air outlet, an intermediate section check valve connected to the intermediate pressure relief outlet and having an air outlet, and an air outlet connected to the exhaust section check valve And an exhaust passage of the outlet of the intermediate section check valve, and a silencer connected to the exhaust passage and having an outlet connected to the final exhaust passage that is open to the atmosphere.

Preferably, the exhaust section check valve, the intermediate section check valve, the exhaust passage, and the muffler are integrally combined into an exhaust unit.

Preferably, the multi-stage positive displacement dry vacuum pump comprises a five-stage dry vacuum pump, and the intermediate pressure relief outlet is connected to the second stage of the five-stage dry vacuum pump.

Preferably, the muffler includes a composite muffler including a resonance type muffler and an expansion type muffler disposed in an upstream region of the muffler with respect to a direction in which the gas flows through the muffler. The expansion type silencer is disposed in a downstream region of the muffler with respect to a direction in which the gas flows through the muffler.

Preferably, the multi-stage positive displacement Roots type dry vacuum pump comprises a single multi-stage positive displacement Roots type dry vacuum pump or a plurality of series multistage positive displacement Roots type dry vacuum pumps.

For the dry vacuum pump device as described above, the exhaust section check valve is connected to the final outlet of the multi-stage positive displacement Roots type dry vacuum pump, and the intermediate section check valve is connected to the middle of the multistage positive displacement Roots type dry vacuum pump. a pressure release outlet, the exhaust passage is connected to an outlet of the exhaust section check valve and an outlet of the intermediate section check valve, and the silencer is connected to the exhaust passage and has a connection to the atmosphere The air outlet of the final exhaust passage. Therefore, the noise from the final outlet exhaust and the noise from the intermediate relief outlet exhaust can be effectively silenced (reduced noise).

In order to achieve the above second object, the present invention provides another dry vacuum pump apparatus comprising a multi-stage Roots type dry vacuum pump having a final outlet for exhausting in a final stage for discharging super-compressed gas in an intermediate stage. The intermediate pressure relief outlet, the exhaust section check line is connected to the final outlet for discharge into the atmosphere, and the intermediate section check valve is connected to the intermediate pressure relief outlet for discharge into the atmosphere.

Preferably, the multi-stage Roots type dry vacuum pump comprises a five-stage Roots type dry vacuum pump comprising each of the five rotor stages, and each of the rotors is disposed in each of the rotor chambers. The intermediate section check valve is in communication with the rotor chamber in the second stage, and the rotor of the rotor chamber disposed in the first stage has an axial width which is the axis of the rotor of the rotor chamber disposed in the second stage Two or more times the width.

Preferably, the second dry vacuum pump further includes an exhaust passage connected to an outlet of the exhaust section check valve and an outlet of the intermediate check valve, and a muffler connected to the outlet The exhaust passage has an air outlet connected to a final exhaust passage that communicates with the atmosphere.

The exhaust section check valve, the intermediate section check valve, the exhaust passage, and the muffler are preferably integrally combined as an exhaust unit.

Preferably, the multi-stage Roots type dry vacuum pump comprises a booster pump and a main pump having a final outlet connected to the main pump, and the exhaust unit is connected to the main pump.

By the dry vacuum pump device described above, the multi-stage Roots type dry vacuum pump has an intermediate pressure relief outlet in the intermediate stage, and the super compressed gas is discharged, and the intermediate section check valve is connected to the intermediate pressure release outlet. The gas is discharged into the atmosphere. As a result, the dry vacuum pump is prevented from operating at a low rotational speed in an overload, and thus the time for discharging the compressed gas can be reduced.

Preferably, the multi-stage Roots type dry vacuum pump comprises the five-stage Roots type dry vacuum pump, the intermediate stage check valve is connected to the rotor chamber in the second stage, and is disposed in the rotor chamber in the first stage. The rotor has an axial width that is two or more times the axial width of the rotor of the rotor chamber disposed in the second stage. The intermediate section check valve is connected to the intermediate pressure relief outlet and is connected to a rotor chamber provided with a high compression ratio in the second stage. As a result, the dry vacuum pump is prevented from operating at a low rotational speed in an overload, and thus the time for discharging the compressed gas can be reduced.

The air outlet of the exhaust section check valve and the outlet of the intermediate section check valve are connected to the exhaust passage, and the silencer is also connected to the exhaust passage. The air outlet of the muffler is connected to the last discharge passage, which is connected to the exhaust port to discharge the gas into the atmosphere. Therefore, the noise from the final outlet exhaust gas and the noise of the super-compressed gas discharged from the intermediate pressure relief outlet can be effectively silenced (reduced noise).

Since the exhaust section check valve, the intermediate section check valve, the exhaust passage, and the muffler are preferably combined as a exhaust unit as a whole, the number of components of the exhaust system of the dry vacuum pump can be reduced, and the row is eliminated. The volume of the gas system is reduced. Therefore, the volume of the dry vacuum pump device is reduced and the manufacturing cost is low.

In order to achieve the above third object, the present invention provides an exhaust unit adapted to be coupled to a multi-stage vacuum pump having a final outlet for exhausting gas in a final stage and for discharging super-compressed gas in an intermediate stage The intermediate pressure relief outlet. The exhaust unit includes an exhaust section check valve adapted to be coupled to a final outlet of the multi-stage vacuum pump, an intermediate section check valve adapted to be coupled to an intermediate relief outlet of the multi-stage vacuum pump, and the exhaust section A muffler connected to the downstream of the intermediate check valve. The exhaust section check valve, the intermediate section check valve, and the muffler are integrally combined with each other.

The exhaust section check valve, the intermediate section check valve, and the muffler connected to the exhaust section check valve downstream of the intermediate section check valve are integrally connected to each other in the exhaust unit In combination, the venting unit is assembled from a smaller number of components and the volume is reduced, which also results in lower manufacturing costs.

The multi-stage vacuum pump can be used as long as the exhaust unit is mounted on the multi-stage vacuum pump such that the final outlet is connected to the exhaust section check valve and the intermediate pressure relief outlet is connected to the intermediate section check valve The exhaust section check valve, the intermediate pressure relief outlet, and the muffler are combined. As a result, they can be easily combined in the dry vacuum pump device, so that the dry vacuum pump device can be reduced in volume and manufacturing cost as the exhaust unit.

In order to achieve the above fourth object, the present invention provides a muffler including a resonance type muffler and an expansion type muffler, the resonance type muffler being disposed in an upstream region in a direction in which a gas flows through the muffler, along which the expansion The type silencer is disposed in a downstream region of the direction in which the gas flows through the muffler. The resonance type silencer and the expansion type silencer are integrally combined.

The present invention also provides a muffler comprising a cover and a muffler housing in the form of a thick plate having a resonance chamber as a resonance type silencer, an expansion chamber as an expansion type muffler, and a sound reduction defined therein a gas passage that is open to the side surface of the housing and that is open in the side surface. The resonant chamber communicates with the gas passage via a resonant port, and the expansion chamber communicates with the gas passage along a throttling throat downstream of the resonant port along a direction in which the gas flows through the sound absorbing housing. The side surface of the muffler housing is covered with a cover, so that the resonance type muffler and the expansion type muffler are combined with each other in a unitary manner.

Since the resonance chamber is disposed in an upstream region along a direction in which the gas flows through the muffler, and the expansion chamber is disposed in a downstream region along a direction in which the gas flows through the muffler, wherein the resonance type muffler and the expansion type muffler Combined with each other in a holistic manner, the silencer silences (reduces noise) the noise in a wide frequency range and reduces the volume of the silencer.

The muffler housing of the composite muffler may have the resonance chamber as the resonance type muffler, the expansion chamber as the expansion type muffler, and the gas passage line defined on a side surface of the muffler case and The side surface is open. The resonant chamber communicates with the gas passage via the resonant opening opening in the side surface, and the expansion chamber flows along the throttle throat downstream of the resonant port along the direction of the gas flowing through the sound absorbing housing The channels are connected. The side surface of the muffler housing is covered with a cover, so that the resonance type muffler and the expansion type muffler are combined with each other in a unitary manner. With this configuration, the muffler can increase the frequency range of noise mute (lower noise) and reduce the volume of the muffler. The expansion chamber may be divided into a first expansion chamber and a second expansion chamber. The resonance chamber and the first expansion chamber can share a wall, and the first expansion chamber and the second expansion chamber can also share a wall, and this will further reduce the volume of the silencer.

The resonance type silencer is disposed in an upstream region along a direction in which the gas flows through the muffler, and is disposed along a downstream portion of the expansion muffler in a direction in which the gas flows through the muffler. As a result, the muffler is capable of making the range of gas eliminator discharge from the dry vacuum pump large to maintain the quietness of the environment including the dry vacuum pump and the muffler. Since the volume of the muffler is reduced, the volume of the dry vacuum pump is also reduced.

The present invention provides another dry vacuum pump apparatus including a pump unit having a rotor housing, a pair of rotating shafts rotatably supported in the rotor housing, and a pair of multi-stage rotor sets fixed to the rotating shafts And a plurality of multi-stage rotor chambers defined in the rotor housing, the rotor groups being disposed in the rotor chambers. The motor unit includes a motor for rotating the rotating shaft to continuously convey the gas compressed by the rotor in the rotor chamber via the respective rotor chambers. And a flange that integrally couples the motor unit to the pump unit, the flange having a coolant passage through which coolant can flow.

By the dry vacuum pump device described above, when the coolant flows through the coolant tube disposed in the flange of the coupling motor unit and the pump unit, heat transferred from the pump unit to the motor housing is absorbed and flows through the The coolant in the coolant passage blocks heat transfer to the motor. As a result, the motor housing does not require any other cooling means to dissipate heat from the pump unit. The width dimension of the motor housing is thus smaller than the conventional motor housing which can internally define a coolant passage.

Furthermore, the present invention can provide another dry vacuum pump device including a rotor housing, a pair of rotating shafts rotatably supported in the rotor housing, and a pair of multi-stage rotor sets fixed to the rotating shafts And a plurality of multi-stage rotor chambers defined in the rotor housing, the rotor assemblies are disposed in the rotor chambers, and the rotor housing has a plurality of gas passages; and the motor unit is adapted to rotate the shaft so that The gas compressed by the rotor in the rotor chamber is continuously conveyed via the respective rotor chambers and gas passages. The rotor housing includes a pair of individual components that each have a mating surface that is secured and locked to each other by a plurality of axially spaced bolts. Each bolt passes through an area of the individual element through which the gas passage is free and between the gas passages immediately adjacent the location defining the gas passage.

By the dry vacuum pump device described above, since the individual components of the rotor housing are connected by the bolts through the region of the individual components through which the gas passage is not passed, and between the gas passages immediately adjacent to the peripheral position defining the gas passages As a result, as a result, the area of each bolt passing through the individual members can be approximated to the inner peripheral surface of the rotor housing, so that the width dimension of the rotor housing can be reduced, making it possible to reduce the volume of the pump unit.

The preferred embodiments of the present invention will be described in detail below with reference to the drawings. 1 is a vertical cross-sectional front view of a dry vacuum pump device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, the dry vacuum pump device including a multi-stage Roots type dry vacuum pump (hereinafter referred to as "Dry vacuum pump" 10, the dry vacuum pump 10 is a five-stage dry vacuum pump and has five stages of Roots type rotor pairs 12a, 12b, 12c, 12d, 12e, which are fixedly mounted on the two rotating shafts 11a, 11b, The two rotating shafts 11a, 11b are rotatably supported by the bearings 20, 21 on opposite ends of the two rotating shafts 11a, 11b. Each of the rotors 12a, 12b, 12c, 12d, and 12e is collectively referred to as "rotor 12" hereinafter.

A small gap is defined between the rotors 12, and a small gap is also defined between the rotors 12 and the periphery of the rotor housing 14, and the rotor housing 14 is rotatably received therein. The rotor 12, therefore, when the two rotating shafts 11a, 11b are rotated along their axes, the rotors 12 are rotated along the axes of the two rotating shafts 11a, 11b without touching each other. Each of the rotor chambers 13a, 13b, 13c, 13d, 13e is defined within the rotor housing 14 and houses each rotor pair 12a, 12b, 12c, 12d, 12e. The gas system extracted by the dry vacuum pump 10 flows through the rotor chambers 13a, 13b, 13c, 13d, and 13e, and is disposed in the rotor casing 14 along the two rotating shafts 11a and 11b in series. The rotor housing 14 has an upper surface covered by a cover member (not shown). The rotor housing 14 has an inlet 17 defined in the upper surface and in communication with the rotor chamber 13a in the first stage. The rotor housing 14 also has an outlet side surface that is secured by a first side housing 26 that is secured to the rotor housing 14. The bearing housing 23 houses the bearing 21 therein and is fixed to a side surface away from the first side housing 26 of the rotor housing 14. The first side housing 26 has a final outlet 18 defined on one side of the surface thereof that faces the rotor housing 14 and communicates with the rotor chamber 13e at the final stage. The final outlet 18 is vented to the atmosphere via the exhaust unit check valve and muffler, please state it later.

As shown in Fig. 1, a motor (e.g., a brushless DC motor) 22 is disposed on the bearing 20 on a side away from the rotor housing 14. The motor 22 has a rotor 22a provided at one of the ends of the two rotating shafts 11a, 11b, and a stator 22b provided around the rotor 22a. The motor 22 is supplied with variable frequency power from a power source (for example, an inverter device or the like (not shown), and includes a software startup mode of the dry vacuum pump 10. The rotational speed is controlled. The motor 22 is housed in the motor housing 24. If the motor 22 includes a brushless DC motor, the rotor 12 is transmitted through the rotating shafts 11a, 11b, and the brushless DC motor is synchronously driven in the opposite direction. In particular, timing gears 29 (which are held together to engage each other) are fixed to the respective ends of the rotating shafts 11a, 11b away from the motor 22. Each of the timing gears 29 and the bearings 21 is housed in the bearing housing 23, and the bearings 20 and 21 are held by the bearing housings 40 and 41, and the bearing housings 40 and 41 are accommodated in the bearing housings 40 and 41, respectively. Inside the motor housing 24 and the bearing housing 23.

In each of the rotor chambers 13a, 13b, 13c, 13d, 13e, gas is confined between the rotors 12 (which are mounted on the rotating shafts 11a, 11b) and the inner peripheral surface of the rotor housing 14 from the rotor chamber. The inlet side is discharged to the outlet side. The rotor housing 14 includes a double-walled housing including inner and outer peripheral walls defining respective gas passages 15a, 15b, 15c, 15d between respective rotor chambers 13a, 13b, 13c, 13d, 13e therebetween 15e. The outlet side of the rotor chamber 13a communicates with the rotor chamber 13b via the gas passage 15a. Similarly, the respective outlet sides of the rotor chambers 13b, 13c, 13d, and 13e communicate with the respective inlet sides of the rotor chambers 13c, 13d, and 13e and the final outlet 18 by the respective gas passages 15b, 15c, 15d, and 15e. Therefore, the gas compressed by the rotor 12a in the rotor chamber 13a is discharged from the outlet side of the rotor chamber 13a to the inlet side of the rotor chamber 13b via the gas passage 15a. Therefore, the gas is continuously compressed in the rotor chambers 13a to 13e, and is discharged into the final outlet 18 via the gas passages 15a to 15e.

In the present embodiment, the axial width of the rotor chamber 13a in the first stage is twice or more the axial width of the rotor chamber 13b of the second stage, in particular, as shown in FIG. 3, in the first stage. The axial width Wa of the rotor 12a is twice or more (Wa ≧ 2Wb) of the axial width Wb of the rotor 12b in the second stage. The axial width Wc of the rotor 12c in the third stage, the axial width Wd of the rotor 12d in the fourth stage, and the axial width We of the final stage rotor 12e are gradually reduced in the stated ratio. The axial width of each of the rotor chambers 13a to 13e is substantially equal to the axial width of each of the rotors 12a to 12e.

In general, in a multi-stage Roots type dry vacuum pump, the capacity of the rotor chamber in the first stage is determined by the discharge speed of the designed vacuum pump. Therefore, if the vacuum pump system is designed to have a high discharge speed, it is necessary to increase the rotor chamber capacity in the initial stage. On the other hand, the capacity of the rotor chamber in the final stage needs to be reduced, the heat generated by the pressure difference before and after the rotor chamber in the final stage (compression heat) is reduced, and the motor that drives the rotor is also reduced against the pressure difference. The energy of loss. However, if the capacity of the rotor chamber in the final stage is reduced, the gas cannot be smoothly discharged. Since there is a trade-off relationship between the volume ratio and heat generation, it is determined whether the volume ratio (compression ratio) is increased or decreased depending on whether the volume ratio or heat is generated when designing the vacuum pump. Stressed.

Further, in the present embodiment, the axial width Wa of the rotor 12a in the first stage is set to be nine times or more (Wa ≧ 9We) of the axial width We of the rotor 12e in the final stage. The ratio of the axial width Wa of the rotor 12a in the first stage to the axial width We of the final stage rotor 12e is equal to the volume ratio of the rotor chamber 13a in the first stage to the final stage rotor chamber 13e.

If the motor 22 includes a brushless DC motor, the rotational speed of the motor 22 can be controlled to increase the exhaust velocity, so that the volume of the final stage rotor chamber 13e becomes smaller, and the heat generated by the motor 22 and the motor 22 are consumed. electric power. In other words, the dry vacuum pump 10 can achieve the same exhaust speed as a conventional vacuum pump using a general motor, and can have a larger volume ratio (compression ratio) and generate less heat than a conventional vacuum pump. The motor 22 using the brushless DC motor has a high efficiency in rotating the two rotating shafts 11a, 11b, and can cope with a large load change, and can generate a large compressive power after the dry vacuum pump 10 is started.

The bearing 21 is disposed close to the final outlet 18 of the dry vacuum pump 10, and the rotating shafts 11a, 11b are rotatably supported by the bearings 21 and the bearings 22 disposed close to the inlet 17. Each bearing 21 is housed in the bearing housing 23, and the first side housing 26 is disposed between the bearing housing 23 and the rotor housing 14. An O-ring seal (sealing unit, not shown) is disposed between the bearing housing 23 and the first side housing 26, thereby sealing a small gap between the bearing housing 23 and the first side housing 26. . Another O-ring seal (sealing unit, not shown) is disposed between the bearing housing 23 and the rotor housing 14, thereby sealing a small gap between the bearing housing 23 and the rotor housing 14. Each of the bearings 20 is housed in the motor housing 24, and the other side housing 30 is disposed between the motor housing 24 and the rotor housing 14. An O-ring seal (sealing unit, not shown) is disposed between the side housing 30 and the rotor housing 14, and another O-ring seal (sealing unit, not shown) is disposed in the side housing 30. Between the motor housing 24.

According to the dry vacuum pump having the above configuration of the present invention, after the motor 22 is activated to rotate the rotary shafts 11a, 11b, the respective rotors 12a, 12b, 12c, 12d, 12e are rotated to rotate the respective rotor chambers 13a, 13b, 13c, 13d, The gas sucked from the inlet 17 is compressed in 13e. When the gas is gradually compressed, it is continuously delivered to the final outlet 18 via the respective gas passages 15a, 15b, 15c, 15d, 15e, from which the compressed gas is directed into the exhaust connected to the final outlet 18. Unit 50. The exhaust unit 50 discharges the gas into the atmosphere. The exhaust unit 50 includes an exhaust section check valve (most terminated return valve) 51, an intermediate section check valve 52, and a muffler 53. The exhaust section check valve 51 is connected to the final outlet 18 via a gas passage 54. The intermediate section check valve 52 is connected to the intermediate pressure relief outlet 19 via a gas passage 55, and the intermediate pressure relief outlet 19 is defined in the rotor housing 14 to communicate with the gas passage 15b (as shown in Fig. 4). ). The intermediate pressure relief outlet 19 is for releasing a gas compressed to a pressure greater than atmospheric pressure from the second gas passage 15b to the atmosphere to reduce the power loss of the dry vacuum pump 10.

Fig. 4 is a view schematically showing the dry vacuum pump 10 and the exhaust unit 50 of the dry vacuum pump unit, and the gas flows therein. As shown in Fig. 4, when the dry vacuum pump 10 is in operation, the gas sucked into the inlet 17 flows through the respective gas passages 15a, 15b, 15c, 15d, 15e and the final outlet 18 to enter the exhaust unit 50. Then, it flows through the exhaust section check valve (most end return valve) 51 and the muffler 53, and is discharged into the atmosphere. For example, if the dry vacuum pump 10 is activated and the gas is continuously compressed in the dry vacuum pump 10, the gas flows from the intermediate pressure relief outlet 19 in communication with the gas passage 15b (the gas passage 15b is in the second stage). The rotor chamber 13b is in communication) and then enters the exhaust unit 50. In the exhaust unit 50, the gas flows through the intermediate section check valve 52 (i.e., prevents the super compression check valve) from entering the muffler 53. As will be described later, the exhaust section check valve 51, the intermediate section check valve 52, and the elimination The sounder 53 is disposed in the exhaust unit 50 in a unitary manner. Therefore, when the exhaust unit 50 is loaded into the dry vacuum pump 10, the exhaust section check valve 51, the intermediate section check valve 52, and the muffler 53 are loaded into the vacuum pump 10.

Fig. 5 schematically shows the structure of the exhaust unit 50. As described above, the vacuum pump 10 includes the respective rotor chambers 13b, 13c, 13d, and 13e. As shown in Fig. 1, each of the rotors 12a, 12b, 12c, 12d, and 12e is provided in each of the rotor chambers 13b, 13c, 13d, and 13e. The gas compressed by the rotor chambers 13a-13e in the vacuum pump 10 and discharged from the final outlet 18 (the final outlet 18 is in communication with the rotor chamber 13e of the final stage) flows through the gas passage in the exhaust unit 50. 54 enters the exhaust section check valve 51. The gas flowing from the exhaust section check valve 51 flows through the exhaust passage 56 provided in the exhaust unit 50 to enter the muffler 53. The intermediate pressure relief outlet 19 (which is in communication with the rotor chamber 13b in the vacuum pump 10) communicates with the intermediate section check valve 52 via a gas passage 55 provided in the exhaust unit 50. When the gas is over-compressed in the vacuum pump 10, the super-compressed gas flows through the intermediate section check valve 52 and the exhaust passage 56 to enter the muffler 53.

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. As shown in FIGS. 6A and 6B, the exhaust unit 50 includes a valve section 50a and a muffling section 50b, and the valve section 50a houses the exhaust section check valve 51 and the intermediate section check valve 52. As shown in Figures 4 and 5, the exhaust section check valve 51 has an inlet that communicates with the final outlet 18 via a gas passage 54. The intermediate section check valve 52 has an inlet that communicates with the intermediate pressure relief outlet 19 via a gas passage 55. The exhaust section check valve 51 and the intermediate section check valve 52 respectively have an outlet that communicates with the exhaust passage 56, and the exhaust passage 56 communicates with the gas passage 61 defined in the muffling section 50b. The muffler section 50b houses the muffler 53 which defines a final discharge passage 56a which extends downstream from the outlet of the muffler 53. The final discharge passage 56a communicates with the exhaust port 58 of the dry vacuum pump unit to discharge the gas into the atmosphere (as shown in Fig. 4).

The gas system flowing through the exhaust section check valve 51 and the intermediate section check valve 52 flows into the muffler 53, and after the noise of the gas is weakened by the muffler 53, the gas system is discharged from the exhaust unit 50. 7A is a side cross-sectional view showing the structure of the muffler 53 in the muffler section 50b, and FIG. 7B is a cross-sectional view taken along line BB of FIG. 7A, the muffler 53 includes a composite muffler. A resonance-type silencer 53-1 and an expansion-type silencer 53-2 are included, and the two are integrally combined. The wall 70 is placed between the resonance type silencer 53-1 and the expansion type silencer 53-2. The resonance type silencer 53-1 and the expansion type silencer 53-2 communicate with the gas passage 61, and the gas passage 61 communicates with the exhaust passage 56. The resonance type silencer 53-1 is disposed upstream of the expansion type silencer 53-2 and flows along the direction in which the gas flows through the muffler 53. In other words, the resonance type silencer 53-1 is placed in the upstream region of the muffler section 50b, and flows along the direction in which the gas flows through the muffler 53, and the expansion type muffler 53-2 is placed downstream of the muffler section 50b. The region flows along the direction in which the gas flows through the muffler 53.

The muffler 53 includes a muffler housing 60 which is in the form of a thick plate and a cover 69, and a side surface of the muffler case 60 defines a groove-shaped gas passage 61 which is a muffler housing. The 60 side surface is open to the outside, and communicates with the exhaust passage 56, the recessed resonance chamber 62, and the recessed first expansion chamber 63 and the recessed second expansion chamber 64 (the recessed resonance chamber 62 is inside the side surface of the muffler housing 60) Opening outward and acting as a resonance type silencer 53-1; and the recessed first expansion chamber 63 and the recessed second expansion chamber 64 are opened outwardly from the side surface of the muffler housing 60 and serve as an expansion type silencer 53-2 ). The muffler housing 60 also has a groove-shaped resonant port 65 that opens outwardly from the side surface of the muffler housing 60 and that communicates the recessed resonance chamber 62 with the gas passage 61. The first throttle throat 66 of the groove configuration is open to the outside from the side surface of the muffler housing 60 and communicates with the recessed first expansion chamber 63 with the gas passage 61; the second throttle throat 67 makes the first expansion chamber 63 The second expansion chamber 64 is in communication; and the third throttle throat 68 allows the second expansion chamber 64 to communicate with the external space.

The side of the muffler housing 60 defines a gas passage 61, a resonance chamber 62, a first expansion chamber 63 and a second expansion chamber 64, and is covered by a cover 69 that encloses the gas passage 61, the resonance chamber 62, and the An expansion chamber 63 and a second expansion chamber 64. The resonance chamber 62 and the first expansion chamber 63 communicate with the gas passage 61 through the resonance port 65 and the first throttle throat 66, respectively. The first expansion chamber 63 and the second expansion chamber 64 communicate with each other through the second throttle throat 67. The second expansion chamber 64 is exhausted to the atmosphere through the third throttle throat 68.

As described above, the muffler 53 includes a composite muffler including the resonance type silencer 53-1 and the expansion type muffler 53-2 housed in the muffler case 60 which is presented in a thick plate form, and The resonance type silencer 53-1 and the expansion type silencer 53-2 are closed by a cover 69. The muffler 53 is flat and has a reduced size, and is composed of a muffler case 60 which is formed in a thick plate form and the cover 69. The gas noise flowing into the gas passage 61 in the muffler section 50b from the exhaust passage 56 in the valve section 50a is silenced by the natural frequency of the resonance type silencer 53-1 combined with the resonance port 65 and the resonance chamber 62. noise). Subsequently, the gas flows through the first throttle throat 66 and enters the first expansion chamber 63, causing the gas to expand and mute (reduce the noise). The gas then flows through the second throttle throat 67 and into the second expansion chamber 64, where the gas is expanded and silenced (lowering noise). Then, the gas flows through the third throttle throat 68, exits the outside of the muffler 53, and enters the atmosphere, and the gas is expanded to silence the gas (lower noise).

The resonance type silencer 53-1 has an advantage in that the volume can be reduced without hindering the flow of gas through the gas passage 61, but the resonance type silencer 53-1 can silence the noise frequency range as compared with the expansion type silencer 53-2. It is relatively narrow. In other words, the inflated silencer 53-2 is capable of canceling noise having a large range of audio frequencies. However, since the range of the frequency at which the expansion type silencer 53-2 can be silenced is inversely proportional to its length, if the noise in the low frequency range is to be silenced, the length of the expansion type silencer 53-2 must be increased. According to the present embodiment, the resilience type silencer 53-1 which can reduce the volume is used to silence the gas noise in the low frequency range, and the frequency range of the mute is the inverse type muffler 53-2 which is inversely proportional to its length, and is used. Silence the remaining high frequency range of gas noise. Therefore, both the resonance type silencer 53-1 and the expansion type silencer 53-2 can be downsized, making it possible to reduce the volume of the entire muffler 53 and to mute (lower noise) noise in a wide frequency range.

The resonance type silencer 53-1 does not hinder the flow of gas into the gas passage 61, even though the composite muffler 53 is exhausted from the gas passage in the exhaust unit 50. In the section, since the resonance type silencer 53-1 is located at the upstream portion of the gas passage 61, any damper capable of detracting the exhaust unit 50 can be minimized.

The valve section 50a and the muffling section 50b of the exhaust unit 50 are integrally combined to form one component of the dry vacuum pump device. As a result, the exhaust unit 50 does not require a line and a joint for connecting the exhaust section check valve 51 to the final outlet 18 of the dry vacuum pump 10; or to connect the intermediate section check valve 52 to the intermediate relief outlet 19 The line and the joint; or the line and joint for connecting the gas passage 61 in the muffler section 50b to the exhaust passage 56 in the valve section 50a. Therefore, the exhaust unit 50 can be assembled from a smaller number of components, and the manufacturing cost is relatively low.

As described above, the exhaust section check valve 51 is connected to the final outlet 18 of the dry vacuum pump 10; and the intermediate section check valve 52 is connected to the intermediate relief outlet 19 of the dry vacuum pump 10. The outlet of the exhaust section check valve 51 and the outlet of the intermediate section check valve 52 are connected to the exhaust passage 56, and the muffler 53 is also connected to the exhaust passage 56. The final discharge passage 56a extends downstream from the muffler 53 to discharge the gas into the atmosphere. With this configuration, the noise from the final outlet 18 and the noise from the intermediate relief outlet 19 can be effectively silenced (reduced noise).

The intermediate pressure relief outlet 19 is disposed in the intermediate stage of the dry vacuum pump 10, and the compression is relatively high, and the intermediate section check valve 52 is connected to the intermediate pressure relief outlet 19, and the super-compressed gas is discharged into the atmosphere. The dry vacuum pump 10 is prevented from operating at a low rotational speed during overload, and thus the time for discharging the compressed gas can be reduced.

In the exhaust unit 50, the exhaust section check valve 51 and the intermediate section check valve 52 in the valve section 50a are integrally combined with the muffler 53 in which the muffler 53 is placed in the exhaust section check valve. 51 is downstream of the intermediate section check valve 52. Therefore, the exhaust unit 50 can be combined by a smaller number of components and is smaller in volume.

The resonance type silencer 53-1 is placed in the upstream region of the muffler section 50b, and flows along the direction in which the gas flows through the muffler 53; and the inflated muffler 53-2 is placed in the downstream region of the muffler section 50b. And along the direction in which the gas flows through the muffler 53. The resonance type silencer 53-1 and the expansion type silencer 53-2 are combined in a unitary manner. Therefore, the muffler 53 can mute the noise in a wide frequency range and can reduce the volume. The muffler 53 is used as a muffler combined with a dry vacuum pump, the volume of the exhaust unit including the muffler can be small, and the volume of the dry vacuum pump capable of muffling noise in a large frequency range can also be reduced.

Figure 8 is a vertical sectional view of another dry vacuum pump device, and Figure 9 is a cross-sectional view taken along line C-C of Figure 8. The components of the dry vacuum pumping apparatus shown in Figs. 8 and 9 are the same or corresponding to those of the dry vacuum pumping apparatus shown in Figs. 1 to 7, and are denoted by the same or corresponding component symbols. The following is not described.

The dry vacuum pump apparatus of this embodiment includes a multi-stage Roots type dry vacuum pump (hereinafter referred to as "dry vacuum pump"), which includes a pump unit P and a motor unit M. The pump unit P of the dry vacuum pump comprises a five-stage pump; and the motor unit M comprises a motor (for example a brushless DC motor) 22.

In Fig. 8, each of the gas passages 15a, 15b, 15c, 15d is defined between the outer and inner peripheral walls of the double-walled rotor housing 14, and the gas passage 15e is omitted from the drawings. This omission is also the same in the description of FIG. 10 below.

According to the dry vacuum pump, the motor unit M has a motor housing 24 coupled to the side housing 30 of the pump unit P by a flange 31 on the side of the motor housing 24, the motor housing 24 and the motor housing 24 The pump unit P is combined. In other words, the motor unit M and the pump unit P are integrally coupled to each other by the flange 31. The gas compressed by the successive rotors 12 in the pump unit P is continuously delivered to the outlet side via the respective gas passages 15a, 15b, 15c, 15d. Since the gas system is compressed by the rotors 12, the heat of compression generated is transmitted to the motor casing of the motor unit M through the rotor housing 14 of the pump unit P, the side casing 30, and the flange 31. Body 24. The heat of compression is transmitted to the bearing housing 23 via the side housing 26 of the pump unit P.

As described above, the heat of compression generated by the compression of the gas by the pump unit P is transmitted to the motor housing 24 of the motor unit M. Therefore, the temperature rise of the motor housing 24 adversely affects the characteristics of the motor 22 housed in the motor housing 24. In the present embodiment, in order to prevent the characteristics of the motor 22 from being adversely affected by heat, the coolant tube 32 is embedded in the flange 31, and the coolant (e.g., cooling water) is supplied to be cooled by the coolant tube 32. The agent passage absorbs and blocks heat transfer from the rotor housing 14 of the pump unit P to the motor housing 24 of the motor unit M. The motor housing 24 of the motor unit M does not require any cooling means to dissipate heat transferred from the pump unit P. The heat generated by the motor housing 24 itself is naturally dissipated by the embedded coolant tube. If the coolant tube 32 is not embedded in the flange 31, the coolant passage may be defined directly within the flange 31.

However, it is customary to embed the coolant tube universally to flow the coolant in the embedded coolant tube to avoid the heat of the motor housing 24 rising due to the heat transferred from the pump unit P to the motor housing 24. Therefore, the motor housing 24 needs to have a large wall thickness, which is an obstacle to the attempt to reduce the size of the motor housing 24. According to this embodiment, the coolant tube 32 is embedded in the flange 31, which has to be thicker due to the need to be fixed to the pump unit P. By embedding the coolant tube 32 in the flange 31, the motor housing 24 does not require any other cooling, and thus the thickness of the motor housing 24 can be reduced to reduce the size and weight of the motor unit M.

As shown in Fig. 9, the pump unit P has a rotor housing 14 including individual upper and lower members 14-1, 14-2, and the upper and lower members 14-1, 14-2 each have a matching surface. A plurality of bolts 34 are fixed to each other and locked together. As indicated by the dashed line in Figure 10 (which shows only the lower element 14'-2), the conventional rotor housing 14' includes individual components 14'-1, 14'-2 which are individual to the embodiments of the present invention. The elements 14-1, 14-2 are also thicker than the wall thickness Δd, and are interlocked with each other by a plurality of bolts 34 (four on each side as shown in Fig. 10), each bolt 34 extending through Each bolt receptacle is defined by a peripheral region of each of the gas passages 15a to 15d of the individual members 14'-1, 14'-2. Although the individual elements 14'-1 are not depicted in FIG. 10, each bolt 34 extends through a bolt receptacle defined in the individual element 14'-1, as well as the extension of each bolt 34 defined by the individual element. Bolt socket in 14'-2. As a result, by the conventional rotor case 14', the wall thickness of the individual elements 14'-1, 14'-2 is thicker than the thickness of the individual elements 14-1, 14-2 in the present embodiment. A wall thickness Δd is produced.

According to the present embodiment, the dry vacuum pump device reduces its compression power while the motor efficiency increases to reduce power consumption. The dry vacuum pump combined with the dry vacuum pump unit is a multi-stage Roots type dry vacuum pump, in which compressed air passes through a vacuum to successive stages of the atmosphere, and then the compressed air is discharged. The dry vacuum pump optimizes the compression ratios of the stages to reduce power consumption by reducing the compression power. In order to optimize the compression ratios of the stages, the dry vacuum pump sets the speed of rotation in order to maintain the required exhaust speed and minimize the resulting mechanical losses. The use of a brushless DC motor is more effective in reducing power consumption. Moreover, according to the present embodiment, the efficiency of the motor can be increased by changing the core material of the motor and improving the winding of the motor.

According to this embodiment, as described above, the compression ratio of the dry vacuum pump is optimized, and the heat generated by the dry vacuum pump is also reduced. Therefore, it is possible to change the position at which the respective bolts 34 lock the individual elements 14-1, 14-2 to each other, thereby reducing the wall thickness of the rotor housing 14. Moreover, the dry vacuum pump has its rotation speed set to reduce the mechanical loss caused by the optimization of the compression ratio of the dry vacuum pump. The speed of rotation is set by this, and the core material of the motor is allowed to be changed, and the winding of the motor is also allowed to be improved to increase the efficiency of the motor. Therefore, the heat generated by the motor 22 can be reduced, and the heat generated by the motor 22 can be dissipated by the coolant flowing through the coolant tubes 32 embedded in the flange 31.

Therefore, as indicated by the solid line in Fig. 10, the bolt insertion holes through which the bolts 34 pass are defined by the regions on which the individual elements 14-1, 14-2 are passed without the gas passages 15a to 15d. The region between the gas passages 15a to 15b, the region between the gas passages 15b to 15c, the region between the gas passages 15c to 15d, and the region on the side of the gas passage 15a away from the gas passage 15b, immediately after The peripheral positions of the gas passages 15a to 15d are defined. Each bolt 34 is inserted into each bolt receptacle to lock the individual components 14-1, 14-2 to each other. Each of the bolt receptacles is located closer to the inner peripheral surface of the rotor housing 14 than the respective bolt receptacles of the conventional rotor housing 14' indicated by the dashed line in FIG. Therefore, the individual elements 14-1, 14-2 of the rotor housing 14 can be reduced in wall thickness in the width direction of the rotor housing 14, thereby reducing the size in the width direction of the dry vacuum pump and thus reducing the volume of the dry vacuum pump unit.

The bearing housing 23 of the pump unit P houses bearings (for example, combined angular ball bearings) 21 and timing gears, which generate heat when the dry vacuum pump unit is operated, that is, due to mechanical loss. In order to reduce the temperature rise due to mechanical loss to cause the temperature of the dry vacuum pump unit to rise, the coolant tube 33 may be embedded in the bearing housing 23 to cause the coolant flow to pass through the coolant passage provided by the coolant tube 33. If the coolant tube 33 is not to be embedded in the bearing housing 23, the coolant passage can be directly defined in the bearing housing 23.

As described above, the coolant tube 32 is fitted into the flange 31, and the motor unit M is coupled to the pump unit P by the flange 31. When the coolant flows through the coolant tube 32, the heat transferred from the pump unit P to the motor housing 24 is absorbed, and the coolant is blocked by the coolant flowing in the coolant tube 32 to transfer heat to the motor 22, and the motor 22 The heat generated by itself naturally dissipates heat from the motor housing 24. As a result, the motor housing 24 does not require any cooling means to dissipate the heat transferred from the pump unit P. The width dimension of the motor housing 24 is thus smaller than that of the conventional motor housing which can internally define a coolant passage.

Figure 11 is a schematic view of a dry vacuum pump apparatus according to another embodiment of the present invention. As shown, the dry vacuum pump apparatus includes a main pump unit MP including a multi-stage Roots type dry vacuum pump 10-2, and a booster pump BP. It contains a multi-stage Roots type dry vacuum pump 10-1. The main pump unit MP has an inlet 17 which is connected to the final outlet 18 of the booster pump BP. The main pump unit MP is connected to the exhaust unit 50, which includes an exhaust section check valve 51, an intermediate section check valve 52, and a muffler 53. The main pump unit MP includes a final outlet 18 connected to the exhaust section check valve 51 and an intermediate relief outlet 19 connected to the intermediate section check valve 52.

In the illustrated embodiment, the muffler 53 includes a compound muffler that includes a resonance type silencer 53-1 and an expansion type muffler 53-2. However, the muffler 53 can also be any muffler that can effectively mute the noise when the super-compressed gas is discharged from the intermediate pressure-release outlet 19 and the noise when it is discharged from the final outlet 18. Furthermore, the intermediate pressure relief outlets 19 and the final outlets 18 can be connected to different silencers, respectively.

The dry vacuum pump of the dry vacuum pump device is not limited to a multi-stage Roots type dry vacuum pump, but may be any other type of dry vacuum pump.

While the invention has been shown and described with reference to the embodiments of the embodiments of the present invention, it is understood that various modifications and changes can be made in the invention without departing from the scope of the appended claims.

10, 10-1, 10-2. . . Dry vacuum pump

11a, 11b. . . Rotating shaft

12 (12a to 12e), 22a. . . Rotor

13a to 13e. . . Rotor chamber

14. . . Rotor housing

14’. . . Conventional rotor housing

14-1, 14-2. . . Individual components

14’-1, 14’-2. . . Conventional individual components

15a to 15e. . . Gas passage

17. . . Entrance

18. . . Final exit

19. . . Intermediate pressure relief outlet

20, 21. . . Bearing

twenty two. . . motor

22b. . . stator

twenty three. . . Bearing housing

twenty four. . . Motor housing

26. . . First side housing

29. . . Timing gear

30. . . Side shell

31. . . Flange

32, 33. . . Coolant tube

34. . . bolt

40, 41. . . Bearing housing

50. . . Exhaust unit

50a. . . Valve section

50b. . . Silencing section

51. . . Exhaust section check valve

52. . . Intermediate check valve

53. . . silencer

53-1. . . Resonant silencer

53-2. . . Inflated silencer

54, 55, 56, 61. . . Gas passage

56a. . . Final discharge channel

58. . . exhaust vent

60. . . Silencing housing

62. . . Resonance chamber

63. . . First expansion chamber

64. . . Second expansion chamber

65. . . Resonance port

66. . . First throttling throat

67. . . Second throttle throat

68. . . Third throttle throat

69. . . cover

70. . . wall

Δd. . . Wall thickness

Wa to We. . . Axial width

1 is a vertical cross-sectional front view of a dry vacuum pump device in accordance with an embodiment of the present invention;

Figure 2 is a cross-sectional view taken along line A-A of Figure 1;

Figure 3 is a front elevational view showing the shaft and rotor of the multi-stage Roots type dry vacuum pump in the dry vacuum pump unit shown in Figure 1;

Figure 4 is a schematic view showing the flow of gas inside the dry vacuum pump device shown in Figure 1;

Figure 5 is a schematic view showing the structure of an exhaust unit of the dry vacuum pump device shown in Figure 1;

Figure 6A is a plan view showing the structure of the exhaust unit of the dry vacuum pump device shown in Fig. 1;

6B is a front view showing the structure of the exhaust unit of the dry vacuum pump device shown in FIG. 1;

Figure 7A is a side cross-sectional view showing the structure of the muffler of the exhaust unit of the dry vacuum pump device shown in Figure 1;

Figure 7B is a cross-sectional view taken along line B-B of Figure 7A;

Figure 8 is a vertical sectional view showing another vacuum pump device of the present invention;

Figure 9 is a cross-sectional view taken along line C-C of Figure 8;

Figure 10 is a view showing a position of a bolt insertion hole through which a lock bolt can be inserted in a rotor case of a multi-stage Roots type dry vacuum pump in the dry vacuum pump device shown in Fig. 8, and showing a bolt insertion hole position of a comparative example ;as well as

Figure 11 is a schematic view of a dry vacuum pump unit in accordance with another embodiment of the present invention.

11a. . . Rotating shaft

12a to 12e, 22a. . . Rotor

13a to 13e. . . Rotor chamber

14. . . Rotor housing

15a to 15e. . . Gas passage

17. . . Entrance

18. . . Final exit

20, 21. . . Bearing

twenty two. . . motor

22b. . . stator

twenty three. . . Bearing housing

twenty four. . . Motor housing

26. . . First side housing

29. . . Timing gear

30. . . Side shell

40, 41. . . Bearing housing

50. . . Exhaust unit

51. . . Exhaust section check valve

52. . . Intermediate check valve

53. . . silencer

Wa to We. . . Axial width

Claims (10)

A dry vacuum pump device for use in a semiconductor manufacturing apparatus, the dry vacuum pump device comprising: a multi-stage positive displacement dry vacuum pump having a final outlet for exhausting gas in a final stage and for discharging super-compressed gas in an intermediate stage An intermediate pressure release outlet; a check valve is connected to the final outlet of the positive displacement dry vacuum pump, and an anti-compression check valve is connected to the intermediate pressure release outlet, the check valve and the foregoing anti-overpressure check valve The air outlet is connected to the exhaust passage, and the exhaust passage is provided with a muffler; the check valve, the anti-overpressure check valve, and the muffler are integrated into one body; the muffler has a resonance type The muffler and the expansion muffler are arranged in series in the order of the resonance muffler and the expansion muffler from the upstream side to the downstream side of the exhaust passage; the structure of the muffler is: a muffler housing and a cover, The muffler case is formed with the exhaust passage, a resonance chamber of the resonance muffler, and an expansion chamber of the expansion muffler, which are covered by the cover Exhaust passage, the resonance chamber, and the opening of the expansion chamber; connected to the exhaust port than the exhaust passage downstream side of the line the muffler. The dry vacuum pump device of claim 1, wherein the multi-stage positive displacement dry vacuum pump is a five-stage vacuum pump, and the intermediate pressure relief outlet is disposed at a second stage of the five-stage vacuum pump. The dry vacuum pump device of claim 1, wherein the multi-stage positive displacement dry vacuum pump device comprises a single multi-stage positive displacement dry vacuum pump or a plurality of multi-stage positive displacement dry vacuum pumps connected in series. The dry vacuum pump device according to claim 1, wherein the multi-stage positive displacement dry vacuum pump is a multi-stage Roots type dry vacuum pump. The dry vacuum pump device of claim 4, wherein the multi-stage Roots type dry vacuum pump comprises a booster pump and a main pump, wherein the booster pump has a final stage outlet connected to the first of the main pump The suction port of the segment, and the exhaust unit in which the check valve, the anti-overpressure check valve, and the muffler are combined into a unitary structure are disposed in the main pump. An exhaust unit for use in a semiconductor manufacturing apparatus having a dry vacuum pump apparatus as described in claim 1, wherein the exhaust unit is connected to a positive displacement dry vacuum pump; and is disposed in an exhaust passage of the exhaust unit a muffler is provided; the muffler has a resonance type muffler and an expansion type muffler, and the resonance type muffler and the expansion type muffler are sequentially disposed from the upstream side to the downstream side of the exhaust passage; the muffler is a structure having a silencing case and a cover, wherein the muffler case is provided with an exhaust passage recess of the exhaust passage, a resonance chamber recess serving as a resonance chamber of the resonance muffler, and expansion of the expansion muffler The expansion chamber recess of the chamber covers the exhaust passage recess, the resonance chamber recess, and the opening of the expansion chamber recess with the cover. A composite type silencer which is a composite type silencer for a vacuum pump, wherein a resonance type muffler is disposed on the upstream side of the gas flow path through which the gas is exhausted from the dry vacuum pump, and an expansion type muffler is disposed on the downstream side, and The resonance muffler and the expansion muffler are integrally configured; the resonance muffler has a resonance chamber, and the resonance chamber communicates with the gas flow passage through a resonance port; and the expansion muffler has a first expansion a chamber and a second expansion chamber, wherein the first expansion chamber communicates with the gas flow passage through a first orifice, and the second expansion chamber communicates with the first expansion chamber through a second orifice, (2) the expansion chamber communicates with the outside through the third orifice, and the gas system enters the first expansion chamber through the first orifice to be expanded and silenced, and enters the second passage through the second orifice. The expansion chamber is expanded and silenced, and finally discharged to the atmosphere through the third orifice to be expanded and silenced. The composite muffler according to claim 7, wherein the composite muffler has a plate-shaped cover and a thick plate-shaped muffler; and a gas flow path concave portion is formed on one side of the muffler case, and the upper portion thereof is Opening the gas passage; the resonance chamber recess has an upper portion that opens to the resonance chamber; the first expansion chamber recess has an upper portion that opens to the first expansion chamber, and a second expansion chamber recess that has an upper portion that is open. And the second expansion chamber; the resonance port recessed portion has an upper portion that is opened to form the resonance port; and the first throttle port recess portion, the second throttle port recess portion, and the third throttle port recess portion, each of which has an upper opening And become The first orifice, the second orifice, and the third orifice; the lid is overlapped with the sound absorbing casing, and the gas passage recess, the resonance chamber recess, and the resonance recess are closed by the cover The opening of the first expansion chamber recess, the second expansion chamber recess, the first throttle recess, the second throttle recess, and the third throttle recess. A dry vacuum pump device comprising a single or a plurality of Roots-type dry vacuum pumps connected in series, an exhaust unit is arranged on the exhaust side of the pump, and an exhaust gas flow path on the exhaust side of the exhaust unit will be The composite muffler described in claim 7 or 8 is provided in such a manner that a gas flow path of the composite muffler is connected to the exhaust gas flow path. The dry vacuum pump device according to claim 9, wherein the exhaust gas flow path of the exhaust unit is provided with a check valve.