WO2019035239A1

WO2019035239A1 - Vacuum exhaust device and method for cooling vacuum exhaust device

Info

Publication number: WO2019035239A1
Application number: PCT/JP2018/012333
Authority: WO
Inventors: 建治橋本; 英晃井上; 浩司柴山; 敏生鈴木
Original assignee: 株式会社アルバック
Priority date: 2017-08-14
Filing date: 2018-03-27
Publication date: 2019-02-21
Also published as: TW201910640A; JPWO2019035239A1; JP6473276B1

Abstract

[Problem] To improve the cooling efficiency of a vacuum exhaust device. [Solution] This vacuum exhaust device is equipped with a vacuum pump, a cooling mechanism, and a blower. The vacuum pump has a pump body, a driving unit for driving the pump body, and a control unit for controlling the driving unit. The cooling mechanism has a cooling circuit, a circulation pump for circulating a refrigerant through the cooling circuit, and an air cooled heat exchanger that is connected to the cooling circuit and can cool the refrigerant. The cooling mechanism cools the control unit with the refrigerant. The blower can blow external air from the vacuum pump toward the air cooled heat exchanger. The blower cools both the control unit and the air cooled heat exchanger with the external air.

Description

Vacuum exhaust system and cooling method of vacuum exhaust system

The present invention relates to an evacuation apparatus and a method of cooling the evacuation apparatus.

Some vacuum pumps, such as a rotary pump, take in wind from the outside and forcibly cool the vacuum pump by air cooling (see, for example, Patent Document 1). On the other hand, there is a type in which lubricating oil is circulated in a pipe, the lubricating oil is cooled by an air-cooled radiator connected to the pipe, and the vacuum pump is cooled by the cooled lubricating oil (see, for example, Patent Document 2).

JP, 2010-127118, A JP 10-159780 A

However, as the required power of the vacuum pump increases, the amount of heat generated from the vacuum pump also increases. As a result, air cooling can not cope with the increase in the required power. On the other hand, in the method of cooling with lubricating oil, if the lubricating oil is contaminated or deteriorated by driving the vacuum pump, the cooling performance may be reduced.

In view of the circumstances as described above, it is an object of the present invention to provide an evacuating apparatus with improved cooling efficiency and a method of cooling the evacuating apparatus.

In order to achieve the above object, an evacuation apparatus according to an aspect of the present invention includes a vacuum pump, a cooling mechanism, and a blower. The vacuum pump has a pump body, a drive unit for driving the pump body, and a control unit for controlling the drive unit. The cooling mechanism includes a cooling circuit, a circulation pump that circulates the refrigerant through the cooling circuit, and an air-cooled heat exchanger connected to the cooling circuit and capable of cooling the refrigerant. The cooling mechanism cools the control unit by the refrigerant body. The blower can blow outside air from the vacuum pump to the air-cooled heat exchanger. The blower air-cools each of the control unit and the air-cooling type heat exchanger by the outside air.
Thus, the control unit is cooled by the refrigerant body cooled by the air-cooled heat exchanger, and the vacuum pump blows the outside air toward the air-cooled heat exchanger, and the external air is controlled before hitting the air-cooled heat exchanger Exposed to department. As a result, the cooling efficiency of the vacuum exhaust system is improved.

The above-described vacuum evacuation apparatus may further include a housing for housing the vacuum pump and the cooling mechanism. The air blower blows the outside air from the vacuum pump toward the air-cooled heat exchanger between the housing and the control unit.
As a result, an air flow is generated by the outside air between the housing and the control unit, and the control unit is efficiently air-cooled.

In the above-described vacuum evacuation device, the control unit may be located between the air-cooled heat exchanger and the pump body.
As a result, the outside air sent by the blower hits the control unit before hitting the air-cooled heat exchanger, and the cooling efficiency of the vacuum exhaust system is improved.

In the above-described vacuum evacuation device, the air-cooled heat exchanger may be located between the blower and the control unit.
Thus, the outside air drawn by the blower hits the controller and then the air-cooled heat exchanger. As a result, the air-cooled heat exchanger is efficiently air-cooled.

In the above-described vacuum evacuation apparatus, the cooling mechanism may further cool the drive unit by the refrigerant circulating in the cooling circuit. In the cooling circuit, the portion for cooling the control unit is located upstream of the portion for cooling the drive unit.
Thus, the refrigerant cooled by the air-cooled heat exchanger cools the control unit in advance and then cools the drive unit. As a result, the cooling efficiency of the vacuum exhaust system is improved.

The above-described evacuation apparatus may further include an auxiliary pump for evacuating the gas exhaust port provided in the pump body.
As a result, the gas exhaust port provided in the pump body is evacuated and the load on the pump body is reduced. As a result, the cooling efficiency of the vacuum exhaust system is further improved.

In the above-described vacuum evacuation device, the cooling circuit may have a differential pressure mechanism which causes a difference in the vapor pressure of the refrigerant in the cooling circuit upstream of the portion for cooling the control unit.
As a result, a difference occurs in the boiling point of the refrigerant between the upstream and the downstream of the differential pressure mechanism, and, for example, the refrigerant evaporates at a temperature lower in the downstream of the differential pressure mechanism than in the upstream. As a result, the controller is deprived of heat due to the vaporization of the refrigerant, and the cooling efficiency of the vacuum exhaust system is further improved.

In order to achieve the above object, a method of cooling a vacuum exhaust apparatus according to an aspect of the present invention comprises a pump body, a drive unit for driving the pump body, and a control unit for controlling the drive unit. And cooling the control unit with a refrigerant cooled by an air-cooled heat exchanger. By blowing the outside air from the vacuum pump toward the air-cooled heat exchanger, the control unit and the air-cooled heat exchanger are each air-cooled by the outside air.
Thus, the control unit is cooled by the refrigerant body cooled by the air-cooled heat exchanger, and the vacuum pump blows the outside air toward the air-cooled heat exchanger, and the external air is controlled before hitting the air-cooled heat exchanger Exposed to department. As a result, the cooling efficiency of the vacuum exhaust system is improved.

As described above, according to the present invention, there are provided a vacuum evacuation device and a cooling method of the vacuum evacuation device with improved cooling efficiency.

It is a schematic block diagram of the evacuation apparatus concerning a 1st embodiment. Figure (a) is a schematic top plan view of the components in the vacuum evacuation system. Figure (b) is a schematic side view of the components in the vacuum evacuation system. It is a schematic cross section which shows the principal part inside a vacuum pump. It is a schematic side layout of the component in the evacuation apparatus which concerns on 2nd Embodiment. It is a schematic upper surface layout figure of the component in the evacuation apparatus which concerns on 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, XYZ axis coordinates may be introduced.

First Embodiment

FIG. 1 is a schematic block diagram of a vacuum evacuation device according to a first embodiment.

The evacuation apparatus 1 includes a vacuum pump 10, a cooling mechanism 20, and a blower 30.

The vacuum pump 10 has a pump body 11, a drive unit 12, and a control unit 13. The pump main body is, for example, a main body that evacuates the vacuum chamber. The drive unit 12 drives the pump body 11. The control unit 13 controls the drive unit 12.

The cooling mechanism 20 has a cooling circuit 21, a circulation pump 22, and an air-cooled heat exchanger 23. The cooling mechanism 20 circulates the refrigerant in the vacuum exhaust device 1 to cool each of the pump main body 11, the drive unit 12 and the control unit 13. The circulation pump 22 is provided in the middle of the cooling circuit 21 to circulate the refrigerant through the cooling circuit 21. In the description regarding the direction in which the refrigerant flows in the cooling circuit 21, the flow-in direction of the refrigerant is defined as "upstream" and the flow-out direction of the refrigerant is defined as "downstream" with respect to a certain part.

The air-cooled heat exchanger 23 is connected to the cooling circuit 21. For example, the air-cooled heat exchanger 23 is provided in the middle of the cooling circuit 21 and is provided downstream of the circulation pump 22. For example, when the circulation pump 22 operates, the refrigerant supplied from the circulation pump 22 flows into the air-cooled heat exchanger 23. The refrigerant is cooled by the air-cooled heat exchanger 23, and the refrigerant immediately after being cooled by the air-cooled heat exchanger 23 flows into the cooling circuit 21 drawn around the control unit 13.

Thereby, in the drive unit 12 and the control unit 13, the control unit 13 is cooled by the refrigerant in advance, and then the drive unit 12 is cooled. That is, the refrigerant body warmed by the drive unit 12 does not flow to the cooling circuit 21 drawn around the control unit 13, but the refrigerant body immediately after being cooled by the air-cooled heat exchanger 23 is near the control unit 13. It flows into the drawn cooling circuit 21. Thereby, the water cooling effect of the control unit 13 is improved. Then, the refrigerant flowing out of the cooling circuit 21 drawn to the drive unit 12 is sucked by the circulation pump 22, and the circulation pump 22 supplies the refrigerant to the air-cooled heat exchanger 23 again. In the vacuum evacuation device 1, this water cooling operation is repeated. In the present embodiment, “water-cooling” includes not only cooling with water but also cooling with coolant liquid, radiator liquid, and the like.

Further, since the cooling mechanism 20 is a circulation type in the vacuum exhaust device 1, it is not necessary to supply the refrigerant to the vacuum exhaust device 1 from outside the vacuum exhaust device 1. For this reason, the freedom degree of installing the cooling mechanism 20 is improved.

Furthermore, the vacuum evacuation device 1 according to the present embodiment also has an air cooling function.

For example, the blower 30 takes in the outside air from the outside of the vacuum exhaust device 1 and blows the outside air from the vacuum pump 10 toward the air-cooled heat exchanger 23. For example, the flow of outside air is schematically shown by arrow A in the figure. Outside air flows beside each of the main pump body 11, the drive unit 12 and the control unit 13, and is blown to the front of the air-cooled heat exchanger 23. The outside air that has hit the air-cooled heat exchanger 23 is sucked by the blower 30 provided next to the air-cooled heat exchanger 23 and released by the blower 30 to the outside of the vacuum evacuation device 1. As a result, each of the main pump body 11, the drive unit 12, the control unit 13, and the air-cooling type heat exchanger 23 is forcedly air-cooled by the outside air. In the vacuum exhaust device 1, this air cooling operation is repeated.

In the vacuum evacuation device 1, the outside air strikes the control unit 13 before it strikes the air-cooled heat exchanger 23. In other words, the outside air warmed against the air-cooled heat exchanger 23 is exhausted to the outside of the vacuum exhaust device 1 by the blower 30, and the outside air before being warmed by the air-cooled heat exchanger 23 hits the control unit 13. Thereby, the air cooling effect of the control unit 13 is improved.

In the vacuum evacuation device 1, a temperature sensor T 1 is attached to the control unit 13, and the measured value detected by the temperature sensor T 1 is sent to the control unit 13. When the temperature of the control unit 13 becomes equal to or higher than the threshold, the control unit 13 can suppress the operation of the drive unit 12 or stop the operation of the drive unit 12.

For example, the control unit 13 controls the switching speed of the transistors in the inverter control circuit of the control unit 13, the output of the circulation pump 22, and the output of the blower 30.

When the temperature of the control unit 13 exceeds a predetermined value, the control unit 13 increases the output of the blower 30, reduces the switching speed of the inverter control circuit, or increases the output of the circulation pump 22. The temperature of the control unit 13 is controlled to be equal to or less than a predetermined value.

In other words, the control unit 13 operates frequently while the vacuum evacuation device 1 is operated. Therefore, it is important to efficiently cool the heat generated from the control unit 13. In the vacuum evacuation device 1 according to the present embodiment, the temperature of the control unit 13 is controlled so that the temperature of the control unit 13 does not exceed 80 ° C. even if the vacuum evacuation device 1 is operated for a long time. The pump main body 11 and the drive unit 12 are naturally set to a desired temperature or less.

Electric power is supplied to each of the drive source 12, the control unit 13, the circulation pump 22, and the blower 30 from the outside of the vacuum exhaust device 1. The evacuation apparatus 1 may include a power supply 40 as an auxiliary power supply for supplying DC power to the control unit 13, the circulation pump 22, and the blower 30.

FIG. 2 (a) is a schematic top plan view of the components in the vacuum exhaust system. FIG. 2 (b) is a schematic side view of the components in the vacuum evacuation system.

In the vacuum evacuation device 1, the vacuum pump 10 and the cooling mechanism 20 are housed in a housing 50. The shape of the housing 50 is, for example, a rectangular parallelepiped. The housing 50 has an opening 50 h capable of sucking in external air. Below the housing 50, a caster mechanism 90 is provided.

In the vacuum evacuation device 1, the pump body 11, the drive unit 12 and the control unit 13, the air-cooled heat exchanger 23, and the blower 30 are arranged in series in this order. In the present embodiment, the disposition direction of these is taken as a series direction (Y-axis direction).

The pump body 11 is located at the front in the series direction. An intake pipe 111 and an exhaust pipe 112 are provided in the pump body 11. The intake pipe 111 is connected to the internal space of a vacuum tank (not shown), and the exhaust pipe 112 is connected to the atmosphere or an auxiliary pump (not shown), a device for processing discharge gas, or the like.

The drive unit 12 is located between the pump body 11 and the air-cooled heat exchanger 23. The air-cooled heat exchanger 23 is located between the blower 30 and the drive unit 12 and the control unit 13. The air-cooled heat exchanger 23 is, for example, a radiator.

The controller 13 is located between the air-cooled heat exchanger 23 and the pump body 11. The control unit 13 is adjacent to the drive unit 12 in a direction (X-axis direction) orthogonal to the series direction. The control unit 13 is attached to the drive unit 12. When an AC motor is applied as a drive source of the drive unit 12, the control unit 13 has, for example, an inverter control circuit that controls the number of rotations of the AC motor.

In the inverter control circuit, since switching operations of switching elements are frequently performed, heat may be generated to a high temperature. When the temperature of the inverter control circuit exceeds the threshold, the inverter control circuit is broken. For this reason, in the evacuation apparatus, it is required to cool the control unit 13 efficiently.

The cooling mechanism 20 is located between the pump body 11 and the blower 30. The circulation pump 22 is aligned with the air-cooled heat exchanger 23 in the X-axis direction. The cooling circuit 21 is connected to the air-cooled heat exchanger 23. The cooling circuit 21 is routed to the drive unit 12. The control unit 13 is cooled by the cooling circuit 21 drawn around the drive unit 12. However, in the cooling circuit 21, the portion P contributing to the cooling of the control unit 13 is located upstream of the portion Q that cools the drive unit 12.

Thus, the refrigerant immediately after being cooled by the air-cooled heat exchanger 23 flows into the portion P earlier than the portion Q. As a result, the drive unit 12 is efficiently water-cooled. Here, the refrigerant body is, for example, any of water, coolant liquid, radiator liquid and the like.

The blower 30 is located at the end of the series direction. The blower 30 has a rotary impeller 31, a rotating shaft 32, and a cover 33. The cover 33 is provided with an opening 33 h for discharging the outside air from the housing 50.

When the blower 30 operates, the outside air is introduced into the housing 50 through the opening 50 h, and the outside air flows between the housing 50 and the vacuum pump 10. Thereafter, the outside air is blown toward the air-cooled heat exchanger 23 and hits the air-cooled heat exchanger 23. Then, the outside air in the housing 50 passes through the impeller 31 and is discharged from the opening 33 h.

In the vacuum evacuation device 1, an air flow is formed between the vacuum pump 10 and the air-cooled heat exchanger 23 between the housing 50 and the control unit 13 so that the outside air flows from the vacuum pump 10. If the vacuum pump 10 and the like are not accommodated by the housing 50, an air flow flowing beside the control unit 13 is unlikely to be formed, and outside air is easily collected near the control unit 13 outside the control unit 13. As a result, the air cooling effect of the control unit 13 is reduced.

In the present embodiment, the vacuum pump 10 and the cooling mechanism 20 are accommodated by the housing 50, and the air flow forcibly flowing sideways of the control unit 13 is forcibly formed. As a result, the outside air around the control unit 13 is less likely to stagnate in the vicinity of the control unit 13, and the air cooling effect of the control unit 13 is improved.

As described above, in the vacuum evacuation device 1, the control unit 13 is efficiently water-cooled from the drive unit 12 side, and is also efficiently air-cooled from the housing 50 side.

Further, the drive unit 12 and the control unit 13 are at the forefront, and the drive unit 12 and the control unit 13, the pump main body 11, the air-cooled heat exchanger 23, and the blower 30 are arranged in series in this order. Even in the serial direction, since the control unit 13 is located upstream of the air flow than the air-cooling heat exchanger 23, the same air cooling effect can be obtained. In the present embodiment, such sequences are also included.

In the case where the direction of the outside air flowing into the housing 50 is opposite to the direction A, that is, when the air flow is generated from the air-cooled heat exchanger 23 toward the vacuum pump 10, the air-cooled heat exchange is performed. Outside air warmed by air-cooling the vessel 23 strikes the control unit 13, which is not preferable.

FIG. 3 is a schematic cross-sectional view showing the main part inside the vacuum pump. The arrangement of the cooling circuit 21 shown in FIG. 3 is an example, and is not limited to this example.

As an example, a twin screw type screw pump is shown in FIG. The vacuum pump 10 according to the present embodiment is not limited to a twin-screw type screw pump, and may be a roots type dry pump, a rotary pump or the like.

In the vacuum pump 10, a pair of

screw rotors

131 and 132 are provided in the pump housing 110. The material of the pump housing 110 is, for example, cast iron. For example, radiation fins (not shown) are provided on the outer periphery of the pump housing 110, and the pump housing 110 is air cooled by the outside air in the housing 50.

The pair of

screw rotors

131 and 132 are arranged in the X-axis direction. The screw rotor 131 has a helical first tooth 131s, and the screw rotor 132 has a helical second tooth 132s that meshes with the first tooth 131s. The number of turns of each of the first teeth 131s and the second teeth 132s is not limited to the illustrated number.

The shaft end 135 of the screw rotor 131 and the shaft end 137 of the screw rotor 132 pass through the pump housing 110. A bearing 140 a is provided between the shaft end 135 and the pump housing 110. A bearing 140 b is provided between the shaft end 137 and the pump housing 110. The shaft end 135 is rotatably supported by the pump housing 110 via the bearing 140 a. The shaft end 137 is rotatably supported by the pump housing 110 via the bearing 140 b. A cover 141 covering the

bearings

140a and 140b is airtightly fixed to the pump housing 110.

Shaft end 136 of screw rotor 131 opposite to shaft end 135 and shaft end 138 of screw rotor 132 opposite to shaft end 137 pass through pump housing 110 on the side opposite to cover 141 Do. A bearing 150 a is provided between the shaft end 136 and the pump housing 110, and a bearing 150 b is provided between the shaft end 138 and the pump housing 110. The shaft end 136 is rotatably supported by the pump housing 110 via the bearing 150 a, and the shaft end 138 is rotatably supported by the pump housing 110 via the bearing 150 b.

The drive unit 12 includes a motor housing 121, a motor 122, a timing gear 123a, and a timing gear 123b. The motor 122, the timing gear 123 a and the timing gear 123 b are accommodated in the motor housing 121. The material of the motor housing 121 is, for example, an aluminum casting.

The motor 122 is configured of, for example, an AC motor or the like. The drive shaft 122 a 0 of the motor 122 is connected to the shaft end 138 of the screw rotor 132. The motor 122 rotates the screw rotor 132 at a predetermined number of rotations. The rotational speed is controlled by the inverter control circuit of the control unit 13.

The timing gear 123 a is attached to the shaft end 136 of the screw rotor 131. The timing gear 123 b is attached to the shaft end 138 of the screw rotor 132. The timing gears 123a and 123b are juxtaposed in the X-axis direction so as to engage with each other. Thus, when the screw rotor 132 rotates, the screw rotor 131 rotates.

Here, on the side of the

bearings

140a, 140b, the space defined by the pump housing 110, the first teeth 131s and the second teeth 132s is taken as the suction chamber 113, and on the side of the

bearings

150a, 150b, the pump housing 110, the first teeth. A space defined by 131s and the second teeth 132s is an exhaust chamber 115. The intake chamber 113 is connected to the intake pipe 111 via the intake port 114, and the exhaust chamber 115 is connected to the exhaust pipe 112 via the exhaust port 116.

The

screw rotors

131 and 132 rotate in opposite directions to each other by the drive of the motor 122. Thereby, for example, the gas in the vacuum chamber is sucked from the intake port 114 and exhausted from the exhaust port 116.

The control unit 13 includes a circuit board 13s and a case 13c that protects the circuit board 13s. The case 13c is provided with an opening 13h through which the outside air flowing into the housing 50 passes as needed. The circuit board 13s includes an inverter control circuit and the like. The motor housing 121 to which the circuit board 13s is attached also serves as a heat sink of the circuit board 13s. The configuration of the control unit 13 is not limited to the illustrated example.

As an example of the cooling circuit 21, a flow path provided in the motor housing 121 is shown in FIG. 3. The cooling circuit 21 may be configured by at least one of such a flow path, a cooling pipe provided outside the motor housing 121, and a joint that connects the cooling pipes. The cooling pipe provided outside the motor housing 121 may be in contact with the motor housing 121 or may be separated from the motor housing 121. Furthermore, the cooling circuit 21 may have a branched structure.

As described above, in the present embodiment, the control unit 13 is air-cooled with respect to the vacuum pump 10 having the pump body 11, the drive unit 12 for driving the pump body 11, and the control unit 13 for controlling the drive unit. The refrigerant is cooled by the refrigerant cooled by the heat exchanger 23. Further, the control unit 13 and the air-cooling heat exchanger 23 are air-cooled with the outside air by blowing the outside air from the vacuum pump 10 toward the air-cooling heat exchanger 23.

In the vacuum evacuation device 1, each of the drive unit 12 and the control unit 13 is water-cooled, and each of the pump body 11, the drive unit 12, the control unit 13, and the air-cooled heat exchanger 23 is forced air-cooled. In the vacuum exhaust device 1, the temperature of the control unit 13 is controlled to be 80 ° C. or lower even when it is operated for a long time, so the inverter control circuit of the control unit 13 generates heat even if it generates heat The control circuit is always set to 80 ° C. or less by water cooling and air cooling. Thus, even if the vacuum exhaust device 1 is operated for a long time, the inverter control circuit is less likely to be damaged.

Second Embodiment

FIG. 4 is a schematic side layout view of components in the vacuum evacuation device according to the second embodiment.

The evacuation apparatus 2 further includes an auxiliary pump mechanism 60 for evacuating the exhaust pipe 112 provided in the pump body 11. The auxiliary pump mechanism 60 includes an auxiliary pump 61, a pipe 62 disposed downstream of the auxiliary pump 61, a pipe 63 disposed upstream of the auxiliary pump 61, and an exhaust pipe 112 between the pipe 62 and the pipe 63. And a check valve 64 provided on the way. The auxiliary pump mechanism 60 may be provided in the housing 50.

As a result, the exhaust pipe 112 provided in the pump body 11 is evacuated, and the exhaust chamber 115 connected to the exhaust pipe 112 is evacuated. For example, when the evacuation of the vacuum chamber by the pump main body 11 is at a termination stage, the discharge amount from the vacuum chamber decreases, and the gas flow rate flowing through the exhaust pipe 112 decreases. Even if the intake and exhaust of the auxiliary pump 61 become more dominant than the displacement of the pump main body 11 and the pipe 63 side becomes a negative pressure with respect to the pipe 62 side, exhausting through the pipe 62 due to the presence of the check valve 64 The gas flowing into the pipe 112 never flows back into the pump body 11. As a result, the auxiliary pump 61 operates with resistance to atmospheric pressure, and the pump main body 11 does not become the operation that receives the differential pressure between the intake chamber 113 and the exhaust chamber 115, and almost idles. . Thereby, the load of the pump main body 11 (rotational load of the screw rotors 131 and 132) is reduced, and heat generation from the pump main body 11 is suppressed. As a result, the cooling efficiency of the vacuum exhaust device 1 is further improved.

Third Embodiment
FIG. 5 is a schematic top plan view of the components of the vacuum exhaust system according to the third embodiment.

In the vacuum evacuation device 3, the cooling mechanism 20 further includes a differential pressure mechanism 25, a pressure gauge 26, and a pressure accumulator 27. The differential pressure mechanism 25 is provided, for example, upstream of the portion P of the cooling circuit 21. By driving the circulation pump 22, a difference occurs in the internal pressure of the cooling circuit 21 between the upstream and the downstream of the differential pressure mechanism 25. In other words, an internal pressure difference of the cooling circuit 21 occurs between the supply side and the suction side of the circulation pump 22. The differential pressure mechanism 25 is, for example, an orifice. The circulation pump 22 is a gas-liquid mixed transfer circulation pump.

For example, the pressure in the cooling circuit 21 downstream of the differential pressure mechanism 25 is set lower than the pressure in the cooling circuit 21 upstream of the differential pressure mechanism 25. For example, assuming that the pressure in the cooling circuit 21 upstream of the differential pressure mechanism 25 is normal pressure (for example, 1 atm), the pressure in the cooling circuit 21 downstream of the differential pressure mechanism 25 is set lower than normal pressure. .

The pressure gauge 26 measures the pressure in the cooling circuit 21 (part Q) between the downstream of the differential pressure mechanism 25 and the circulation pump 22. The pressure value measured by the pressure gauge 26 is fed back to the output of the circulation pump 22. Thereby, for example, the pressure in the portion Q of the cooling circuit 21 is kept constant.

The pressure accumulator 27 is provided in the cooling circuit 21 between the upstream of the differential pressure mechanism 25 and the circulation pump 22. For example, the pressure accumulator 27 is provided between the air-cooled heat exchanger 23 and the circulation pump 22. When the pressure in the cooling circuit 21 between the upstream of the differential pressure mechanism 25 and the circulation pump 22 becomes equal to or higher than a predetermined value (for example, 1.1 atmospheric pressure or more), the pressure accumulator 27 It has a leak valve that reduces the pressure.

For example, when the refrigerant is water, the boiling point of the refrigerant in the portion Q of the cooling circuit 21 is set to be 80% or less of the set temperature (for example, 80 ° C.) of the control unit 13. For example, the boiling point of the refrigerant in the portion Q of the cooling circuit 21 is set to 64 ° C. or less. Further, the lower limit of the boiling point of the refrigerant may be the dew point of the use environment. This is because when the temperature of the control unit 13 reaches a temperature equal to or lower than the dew point, dew condensation occurs in the electronic circuit to cause a problem. For example, by setting the lower limit of the boiling point of the refrigerant to 40 ° C., the occurrence of condensation can be reliably prevented.

Thereby, even if the temperature of the refrigerant body in the portion Q of the cooling circuit 21 rises due to the movement of the vacuum exhaust device 3, the cooling circuit 21 is obtained when the temperature of the refrigerant body in the portion Q of the cooling circuit 21 reaches 64 ° C. In the portion Q of the refrigerant body, the refrigerant is vaporized. As a result, heat equivalent to the heat of vaporization of the refrigerant is further removed from the drive unit 12 and the control unit 13, and the cooling efficiency of the vacuum exhaust device is further improved. That is, even if the vacuum evacuation device is operated for a long time, the control unit 13 more surely reaches the set temperature (for example, 80 ° C.) or less.

As mentioned above, although embodiment of this invention was described, this invention is not limited only to the above-mentioned embodiment, of course, a various change can be added. Each embodiment is not limited to an independent form, and can be combined as much as technically possible.

DESCRIPTION OF

SYMBOLS

1, 2, 3, 4 ... Vacuum exhaust system 10 ... Vacuum pump 11 ... Pump main body 12 ... Drive part 13 ... Control part 13s ... Circuit board 13c ... Case 13h ... Opening 20 ... Cooling mechanism 21 ... Cooling circuit 22 ... Circulation pump 23 ... Air-cooled heat exchanger 25 ... Differential pressure mechanism 26 ... Pressure gauge 27 ... Pressure accumulator 30 ... Blower 31 ... Impeller 32 ... Rotor shaft 33 h ... Opening 33 ... Cover 40 ... Power supply 50 ... Housing 50 h ... Opening 60 ... Auxiliary pump Mechanism 61 ...

Auxiliary pump

62, 63 ... Piping 64 ... Check valve 70 ... Control device 90 ... Caster mechanism 110 ... Pump housing 111 ... Intake pipe 112 ... Exhaust pipe 113 ... Intake chamber 114 ... Intake port 115 ... Exhaust chamber 116 ... Exhaust Port 121: Motor housing 122: Motor 122a:

Drive shaft

123a, 123b: Timing gear 131, 132: Screw screw 131 131s ···

first tooth

135, 136 · · · shaft end 132s · · ·

second tooth

137, 138 · · ·

shaft end

140a, 140b, 150a, 150b ... bearing 141 ... cover

Claims

A vacuum pump having a pump body, a drive unit for driving the pump body, and a control unit for controlling the drive unit;
The control unit includes a cooling circuit, a circulation pump that circulates a coolant through the cooling circuit, and an air-cooled heat exchanger connected to the cooling circuit and capable of cooling the coolant. A cooling mechanism for cooling the
An exhaust system comprising: an air blower capable of blowing outside air from the vacuum pump toward the air-cooled heat exchanger, and air-cooling each of the control unit and the air-cooled heat exchanger by the outside air.
The vacuum evacuation apparatus according to claim 1, wherein
The apparatus further comprises a housing for housing the vacuum pump and the cooling mechanism,
The air blower blows the outside air from the vacuum pump toward the air-cooled heat exchanger between the housing and the control unit.
The vacuum exhaust system according to claim 1 or 2, wherein
The control unit is located between the air-cooled heat exchanger and the pump body.
The vacuum exhaust system according to any one of claims 1 to 3, wherein
The air-cooled heat exchanger is located between the blower and the control unit.
The vacuum exhaust system according to any one of claims 1 to 4, wherein
The cooling mechanism further cools the drive unit by the refrigerant circulating in the cooling circuit.
In the cooling circuit, a portion for cooling the control unit is located upstream of a portion for cooling the drive unit.
The vacuum evacuation apparatus according to any one of claims 1 to 5, wherein
A vacuum exhaust system further comprising an auxiliary pump for evacuating a gas exhaust port provided in the pump body.
The vacuum exhaust system according to any one of claims 5 or 6, wherein
The cooling circuit includes a differential pressure mechanism that causes a difference in the vapor pressure of the refrigerant in the cooling circuit upstream of the portion that cools the control unit.
With respect to a vacuum pump having a pump body, a drive unit for driving the pump body, and a control unit for controlling the drive unit, the control unit is cooled by a refrigerant body cooled by an air-cooled heat exchanger.
A cooling method of a vacuum exhaust system, wherein the control unit and the air-cooled heat exchanger are each air-cooled with the ambient air by blowing the ambient air from the vacuum pump toward the air-cooled heat exchanger.