JP2001271777A - Cooling device in vacuum pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adequately cool plural cooling regions in a vacuum pump with only a single cooling liquid supply system. SOLUTION: A cooler 44 is installed in a rotor housing 12, and a cooler 45 is installed in a rear housing 14 and a driving part 33. A cooler 46 is installed in a controller 37, and a cooler 47 is installed in an inverter 38. A cooler 48 is mounted on the circumferential surface of a motor M. The coolers 46, 47, 48 are placed midway in a main supply pipe 49. The coolers 44, 45 are placed midway in a sub-supply pipe 50. A polenoid three-way valve 51 placed in the branch part of the main supply pipe 49 and the sub-supply pipe 50 receives exiting demagnetization control of the controller 37.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a vacuum pump which provides a suction effect by a transfer operation of a gas transfer body.

[0002]

2. Description of the Related Art In a vacuum pump disclosed in Japanese Patent Application Laid-Open No. 5-118290, a pair of rotors is rotated in a meshed state. The rotating operation of the plurality of rotors rotating while meshing transfers the exhaust gas. Such a vacuum pump is provided with a cooling device for removing heat generated in a process of compressing exhaust gas. Generally, a cooling device cools the surface of a housing containing a rotor.

[0003]

In a vacuum pump in which a rotor is driven by an electric motor, it is necessary to cool the electric motor and also to cool a control unit for electrically controlling the electric motor. If each unit of the housing, the electric motor, and the control unit is to be cooled by a cooling device having a plurality of independent cooling liquid supply systems, the vacuum pump becomes large. If the housing, the electric motor, and the control unit are cooled by a cooling device having only a single cooling liquid supply system, the size of the vacuum pump can be suppressed. However, since the required amounts of coolant in the cooling areas such as the housing, the electric motor, and the control unit are different, it is not possible to properly cool all the cooling areas with only a single coolant supply system.

It is an object of the present invention to appropriately cool a plurality of cooling areas in a vacuum pump with only a single cooling liquid supply system.

[0005]

According to the first aspect of the present invention, there is provided a main supply path which is provided so as to cool at least one of a plurality of cooling areas in a vacuum pump and supplies a cooling liquid; A sub-supply path arranged to cool at least one of the plurality of cooling areas and supplying the cooling liquid from the main supply path; and a supply-permitted state of supplying the cooling liquid to the sub-supply path. A supply switching unit configured to switch to a supply prohibition state in which the cooling liquid is not supplied to the sub supply path side.

When the supply switching means is in the supply permitting state, the coolant in the main supply path is supplied to the sub supply path. When the supply switching unit is in the supply prohibition state, the coolant in the main supply path is not supplied to the sub supply path. The configuration in which the supply switching means is switched between the supply-permitted state and the supply-prohibited state is effective in properly cooling the cooling area cooled by the supply of the coolant to the sub-supply path with only a single coolant supply system. is there.

According to a second aspect of the present invention, in the first aspect,
Switching control means for electrically switching the supply switching means between a supply permission state and a supply prohibition state,
The cooling area cooled by the cooling liquid supplied to the sub-supply path, or temperature detection means for detecting the temperature of the sub-supply path, the switching control means based on the temperature detection information of the temperature detection means The supply switching means is controlled so that the temperature of the cooling area cooled by the cooling liquid supplied to the sub-supply path converges to a predetermined temperature.

When the temperature detected by the temperature detecting means exceeds a predetermined temperature, the switching control means sets the supply switching means to a supply permitting state. When the supply switching unit enters the supply permission state, the cooling liquid is supplied to the sub-supply path, and the temperature of the cooling area cooled by the cooling liquid supplied to the sub-supply path decreases. When the temperature detected by the temperature detecting means does not reach the predetermined temperature, the switching control means sets the supply switching means to the supply prohibiting state. When the supply switching unit enters the supply prohibition state, the temperature of the cooling area increases.

According to a third aspect of the present invention, in the second aspect,
The switching control means is cooled by a coolant on the main supply path, and the switching control means is located upstream of the supply switching means with respect to the main supply path.

[0010] The high temperature of the switching control means for electrically switching and controlling the supply switching means results in poor control. The configuration in which the switching control means is cooled on the upstream side of the supply switching means is effective in reliably avoiding a control failure due to a high temperature of the switching control means.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the gas transfer body is driven by an electric motor, and the electric motor is cooled by a cooling liquid on the main supply path. The electric motor is located upstream of the supply switching unit with respect to the main supply path.

Higher temperatures of the electric motor shorten the life of the electric motor. The configuration in which the electric motor is cooled on the upstream side of the supply switching means is effective in avoiding shortening the life of the electric motor due to the high temperature of the electric motor.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the vacuum pump has a plurality of rotating shafts arranged in parallel and a rotor arranged on each of the rotating shafts. Multi-stage roots formed in a rotor housing such that rotors on adjacent rotating shafts are engaged with each other and a plurality of pump chambers accommodating a plurality of meshed rotors as a set are arranged in the axial direction of the rotating shafts. A pump is provided, and a cooling area cooled by the coolant on the sub-supply path is the rotor housing forming the pump chamber.

A multi-stage roots pump is suitable as an object to which the present invention is applied. According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the supply switching means is an electromagnetic three-way valve interposed at a branch portion between the main supply path and the sub supply path.

An electromagnetic three-way valve is suitable as a supply switching means. In the invention of claim 7, claims 1 to 5
In any one of the above, the supply switching means is an electromagnetic on-off valve interposed on the auxiliary supply path.

The electromagnetic on-off valve is suitable as a supply switching means.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is embodied in a multi-stage roots pump will be described below with reference to FIGS.

As shown in FIG. 2, the multi-stage roots pump 11
The front housing 13 is joined to the front end of the rotor housing 12 of the first embodiment, and the closing body 10 is joined to the front housing 13. A rear housing 14 is joined to the rear end of the rotor housing 12. The rotor housing 12 includes a cylinder block 15 and a plurality of partition walls 1.
6 As shown in FIGS. 3A, 3B, and 3C, the cylinder block 15 includes a pair of block pieces 17,
Consists of eighteen. As shown in FIGS. 3A and 3B, each partition 16 is composed of a pair of wall pieces 161 and 162. As shown in FIG. 2, the space between the front housing 13 and the partition 16, the space between the adjacent partition 16, and the space between the rear housing 14 and the partition 16 are each a pump chamber 3.
9, 40, 41, 42, 43.

A pair of rotating shafts 19 and 20 are rotatably supported by the front housing 13 and the rear housing 14 via radial bearings 21, 21A, 22, 22A. Both rotating shafts 19 and 20 are arranged parallel to each other. The rotating shafts 19 and 20 are passed through the partition 16. The rotating shaft 19 has a plurality of rotors 23, 24, 25, 26,
27 are integrally formed, and the same number of rotors 28, 29, 30, 31, 32 are integrally formed on the rotating shaft 20. The rotors 23 to 32 are connected to the axis 19 of
When viewed in the directions of 1,201, they have the same shape and the same size. The thickness of the rotors 23, 24, 25, 26, 27 is reduced in this order, and the rotors 28, 29, 3
The thicknesses of 0, 31, and 32 become smaller in this order. The rotors 23 and 28 are housed in a pump chamber 39 in a state where they mesh with each other, and the rotors 24 and 29 are housed in a pump chamber 40 in a state where they mesh with each other. The rotors 25 and 30 are housed in the pump chamber 41 in a state of meshing with each other, and the rotors 26 and 31 are housed in the pump chamber 42 in a state of meshing with each other. Rotors 27, 32
Are housed in the pump chamber 43 in a state of meshing with each other.

A drive section 33 is mounted on the rear housing 14. The rotating shafts 19 and 20 are for the rear housing 1
4 and protrudes into the drive unit 33, and each rotating shaft 1
Gears 34 and 35 are fastened to the projecting ends of the gears 9 and 20 in a state where the gears 34 and 35 mesh with each other. The rotation shaft 19 is shown in FIGS.
3 (a), (b),
It is rotated in the direction of arrow R1 in (c). The rotation of the rotating shaft 19 is transmitted to the rotating shaft 20 via gears 34 and 35, and the rotating shaft 20 is opposite to the rotating shaft 19 as shown by an arrow R2 in FIGS. 3 (a), 3 (b) and 3 (c). Rotate in the direction.

As shown in FIG. 2 and FIG.
A passage 163 is formed in 6. As shown in FIG. 3B, an inlet 164 and an outlet 165 of the passage 163 are formed in the partition 16. Adjacent pump chamber 39,4
0, 41, 42, 43 communicate with each other via a passage 163.

As shown in FIG. 3A, the block 18
Is formed so that a gas inlet 181 communicates with the pump chamber 39. As shown in FIG. 3C, a gas outlet 171 is formed in the block piece 17 so as to communicate with the pump chamber 43. Pump room 3 from gas inlet 181
The gas introduced into 9 is transferred from the inlet 164 of the partition 16A via the passage 163 to the adjacent pump chamber 40 through the passage 163 by the rotation of the rotors 23 and 28. Hereinafter, similarly, the gas is transferred in the order of decreasing the volume of the pump chamber, that is, in the order of the pump chambers 40, 41, 42, and 43. The gas transferred to the pump chamber 43 is discharged from the gas discharge port 171 to the outside. The rotors 23 to 32 are gas transfer bodies that transfer gas.

As shown in FIG. 1, the multi-stage roots pump 11
Are housed in a case 36. A controller 37 and an inverter 38 for controlling the electric motor M are mounted in the case 36. A cooler 44 is provided on the upper surface of the rotor housing 12, and a cooler 45 is provided on the upper surfaces of the rear housing 14 and the drive unit 33. A cooler 46 is provided on an upper surface of the controller 37, and a cooler 47 is provided on an upper surface of the inverter 38. A cooler 48 is mounted on the peripheral surface of the electric motor M.

A cooler 46 for cooling the controller 37;
A cooler 47 for cooling the inverter 38 and a cooler 48 for cooling the electric motor M are interposed in the middle of a main supply pipe 49 for supplying a coolant. Cooler 4 for cooling rear housing 14 and drive unit 33
5 and a cooler 4 for cooling the rotor housing 12
4 is interposed in the middle of the sub supply pipe 50 for supplying the cooling liquid. An electromagnetic three-way valve 51 is interposed at a branch between the main supply pipe 49 and the sub supply pipe 50. At the junction of the main supply pipe 49 and the sub supply pipe 50, a junction pipe 52 having a backflow prevention function is interposed.

As shown in FIG. 5A, the electromagnetic three-way valve 51 has a demagnetized state in which the supply of the coolant to the sub-supply pipe 50 is prohibited (supply prohibited state), and as shown in FIG. Is switched to an excitation state (supply allowable state) in which supply of the coolant to the sub supply pipe 50 is permitted. Coolant is sent to the main supply pipe 49 from a coolant supply source (not shown). The coolant supply source sends the coolant at a predetermined temperature and a constant supply amount (supply amount per unit time) to the main supply pipe 49. The cooling liquid sent to the main supply pipe 49 passes through the coolers 46, 47, and 48 in this order. When the electromagnetic three-way valve 51 is in the supply-prohibited state (demagnetized state), the coolant that has passed through the cooler 48 flows to the merge pipe 52 via the main supply pipe 49. When the electromagnetic three-way valve 51 is in the supply permitting state (excited state), the coolant that has passed through the cooler 48 is
It flows to the coolers 45 and 44 via 0.

A temperature detector 53 is mounted on the surface of the rotor housing 12. The temperature detector 53 detects the temperature of the surface of the rotor housing 12. The temperature detection information obtained by the temperature detector 53 as the temperature detection means is sent to the controller 37. The controller 37 controls the excitation and demagnetization of the electromagnetic three-way valve 51 based on the temperature detection information obtained from the temperature detector 53.

When the detected temperature Tx detected by the temperature detector 53 exceeds a preset target temperature T1, the controller 37 commands the excitation of the electromagnetic three-way valve 51. The electromagnetic three-way valve 51 excites based on an excitation command from the controller 37. The excited electromagnetic three-way valve 51 allows the flow of the coolant from the main supply pipe 49 to the sub-supply pipe 50 and prevents the flow of the coolant to the merge pipe 52 via the main supply pipe 49. Therefore, the temperature in the coolers 45 and 44 decreases, and the cooling action in the coolers 45 and 44 increases. When the detected temperature Tx is equal to or lower than the target temperature range T1, the controller 37 commands the demagnetization of the electromagnetic three-way valve 51. The electromagnetic three-way valve 51 is
Degauss based on a degauss command from controller 37. The demagnetized electromagnetic three-way valve 51 is connected from the main supply pipe 49 to the sub supply pipe 50.
And the flow of the coolant to the merging pipe 52 via the main supply pipe 49 is allowed. Therefore, the temperature in the coolers 45 and 44 increases, and the cooling action in the coolers 45 and 44 decreases. Such control of the cooling action causes the temperature of the surface of the rotor housing 12 to converge to the target temperature T1.

The controller 37 serves as switching control means for electrically switching and controlling the electromagnetic three-way valve 51 between a supply permitted state and a supply prohibited state. The electromagnetic three-way valve 51 is connected to the main supply pipe 49.
And a supply switching means interposed at a branch portion between the auxiliary supply pipe 50 and the auxiliary supply pipe 50. The main supply pipe 49 and the coolers 46, 47, 48 constitute a main supply path. Sub-supply pipe 50 and cooler 44,
45 constitutes a sub supply path.

In the first embodiment, the following effects can be obtained. (1-1) The coolant supplied from the coolant supply source to the main supply pipe 49 at a predetermined temperature and a constant supply amount is supplied to the coolers 46 and 4.
After passing through 7 and 48, the controller 37, the inverter 38 and the electric motor M are cooled. When the electromagnetic three-way valve 51 serving as the supply switching unit is in the supply permission state, the coolant in the main supply pipe 49 that has passed through the electric motor M is supplied to the sub supply pipe 50. When the electromagnetic three-way valve 51 is in the supply prohibited state, the coolant in the main supply pipe 49 is not supplied to the sub supply pipe 50.
The rotor housing 12 and the drive unit 33, which are cooled by the coolant passing through the sub-supply pipe 50, are a cooling area cooled by the coolant supplied to the sub-supply path. The rotor housing 12 and the drive unit 33 are cooled by intermittently supplying the coolant to the sub supply pipe 50 by appropriately switching the electromagnetic three-way valve 51 between the supply permission state and the supply inhibition state.

The controller 37, the inverter 38, and the electric motor M are simple cooling regions in which the cooling can be performed to a desired temperature or lower. However, depending on the type of exhaust gas (for example, perfluorocarbon (PFC) gas or the like) in the pump chambers 39 to 43 for performing gas compression, the exhaust gas may be solidified if the temperature is too low. Solidification of the exhaust gas shortens the life of the vacuum pump. Therefore, the rotor housing 1
Reference numeral 2 is not a simple cooling region in which cooling only to a desired temperature or lower is required.

Further, there is a possibility that the exhaust gas may enter the driving section 33 along the peripheral surfaces of the rotating shafts 19 and 20, and the driving section 33
It is necessary to perform cooling in consideration of the solidification of the invading exhaust gas. That is, it is not a simple cooling area in which the drive unit 33 only needs to be cooled to a desired temperature or lower.

If the excitation and demagnetization control of the electromagnetic three-way valve 51 which is switched between the supply permitted state and the supply prohibited state is properly performed, the rotor housing 12 and the drive unit 33 can be properly cooled. The configuration in which the coolant is intermittently supplied to the coolers 45 and 44 by the excitation / demagnetization switching of the electromagnetic three-way valve 51 is only a single coolant supply system including the main supply pipe 49 and the sub supply pipe 50, and the controller 37 and the inverter 38, it is possible to appropriately cool each cooling area of the electric motor M, the drive unit 33, and the rotor housing 12.

(1-2) A temperature detector 53 is provided on the surface of the rotor housing 12 which is cooled by the supply of the cooling liquid to the sub supply pipe 50, and the temperature of the rotor housing 12 is controlled by the temperature detector 53. Is detected. Controller 37
Is based on the temperature of the rotor housing 12.
It controls the supply of coolant to zero. The configuration in which the temperature of the cooling region of the rotor housing 12 is controlled while detecting the temperature of the cooling region is suitable for appropriately cooling the cooling region of the rotor housing 12.

(1-3) A CPU is used for the controller 37 which issues a command to the electromagnetic three-way valve 51 based on the temperature detection information. Such a high temperature of the controller 37 and the inverter 38 that controls the electric motor M causes control failure. The controller 37 serving as the switching control means is located upstream of the electromagnetic three-way valve 51 with respect to the main supply pipe 49, and the controller 37 and the inverter 38 are constantly cooled by the coolant in the main supply pipe 49. The configuration in which the controller 37 and the inverter 38 are constantly cooled upstream of the electromagnetic three-way valve 51 is effective in reliably avoiding a control failure due to a high temperature of the controller 37 and the inverter 38.

(1-4) The increase in the temperature of the electric motor M shortens the life of the electric motor M. The electric motor M is located upstream of the electromagnetic three-way valve 51 with respect to the main supply pipe 49, and the electric motor M
Is constantly cooled by the cooling liquid in the main supply pipe 49. The configuration in which the electric motor M is always cooled upstream of the electromagnetic three-way valve 51 is effective in avoiding shortening the life of the electric motor M due to a high temperature.

(1-5) The multi-stage roots pump 11 which provides a suction effect while compressing the exhaust gas is suitable as an object to which the present invention is applied. (1-6) The single electromagnetic three-way valve 51 is suitable as supply switching means.

Next, the second of FIGS. 6 and 7A and 7B
An embodiment will be described. The same components as those in the first embodiment are denoted by the same reference numerals. In this embodiment, an electromagnetic on-off valve 54 is interposed on the sub supply pipe 50. The electromagnetic on-off valve 54 is subjected to the excitation / demagnetization control of the controller 37A. When the detected temperature Tx detected by the temperature detector 53 exceeds the preset target temperature T1, the controller 37A commands the electromagnetic on-off valve 54 to be excited. The electromagnetic on-off valve 54 excites based on an excitation command from the controller 37A. FIG.
As shown in (b), the energized electromagnetic on-off valve 54 allows the flow of the coolant from the main supply pipe 49 to the sub supply pipe 50. Therefore, the temperatures in the coolers 45 and 44 decrease,
The cooling action in the coolers 45 and 44 is enhanced. When the detected temperature Tx is equal to or lower than the target temperature T1, the controller 37A commands the demagnetization of the electromagnetic on-off valve 54. The solenoid on-off valve 54 is demagnetized based on a demagnetization command from the controller 37A. FIG. 7 (a)
As shown in (5), the de-energized electromagnetic on-off valve 54 inhibits the flow of the coolant from the main supply pipe 49 to the sub supply pipe 50. Therefore, the temperature in the coolers 45 and 44 increases, and the cooling action in the coolers 45 and 44 decreases. Such control of the cooling action causes the temperature of the surface of the rotor housing 12 to converge to the target temperature T1.

The controller 37A serves as switching control means for electrically switching and controlling the electromagnetic on-off valve 54 between a supply permitted state and a supply prohibited state. The solenoid on-off valve 54 is
It becomes the supply switching means interposed in the middle of 0.

In the second embodiment, the same effects as in the items (1-1) to (1-5) in the first embodiment can be obtained. Further, the electromagnetic on-off valve 54 is suitable as a supply switching means.

Next, a third embodiment shown in FIGS. 8 to 11 will be described. The same components as those in the second embodiment are denoted by the same reference numerals. As shown in FIG. 8, a first electromagnetic on-off valve 54 is interposed on the sub supply pipe 50, and a first electromagnetic on-off valve 54 is provided on the main supply pipe 49 downstream of a branch portion between the main supply pipe 49 and the sub supply pipe 50. Two electromagnetic on-off valves 55 are interposed. The first solenoid on-off valve 54 and the second solenoid on-off valve 55 are subjected to the excitation / demagnetization control of the controller 37B. The electric motor M has a temperature detector 56.
Is attached. The temperature detector 56 detects the temperature of the electric motor M. The controller 37B includes the temperature detector 5
Excitation / demagnetization control of the solenoid on-off valves 54 and 55 is performed based on the temperature detection information obtained from the sensors 3 and 56.

It is assumed that the detected temperature Ty detected by the temperature detector 56 exceeds a preset reference temperature T2. The detected temperature T detected by the temperature detector 53
When x exceeds the preset target temperature T1, the controller 37B commands the excitation of the first solenoid on-off valve 54 and the second solenoid on-off valve 55. The first solenoid on-off valve 54 and the second
The electromagnetic on-off valve 55 is excited based on an excitation command from the controller 37B. As shown in FIG.
The electromagnetic on-off valve 54 allows the flow of the coolant from the main supply pipe 49 to the sub-supply pipe 50, and the excited second electromagnetic on-off valve 55 moves to the merging pipe 52 side via the main supply pipe 49. Block the flow of coolant. Therefore, the temperature in the coolers 45 and 44 decreases, and the cooling action in the coolers 45 and 44 increases. When the detected temperature Tx is equal to or lower than the target temperature T1, the controller 37B commands demagnetization of the first electromagnetic on-off valve 54 and the second electromagnetic on-off valve 55. The first solenoid on-off valve 54 and the second
The electromagnetic open / close valve 55 demagnetizes based on a demagnetization command from the controller 37B. As shown in FIG. 9, the demagnetized first electromagnetic on-off valve 54 inhibits the flow of the coolant from the main supply pipe 49 to the sub-supply pipe 50, and the demagnetized second electromagnetic on-off valve 5
5 allows the flow of the coolant to the merging pipe 52 side via the main supply pipe 49. Therefore, the temperature in the coolers 45 and 44 increases, and the cooling action in the coolers 45 and 44 decreases.

It is assumed that the detected temperature Ty detected by the temperature detector 56 is lower than a preset reference temperature T2. When the detected temperature Tx detected by the temperature detector 53 exceeds the target temperature T1 set in advance, the controller 37B commands the excitation of the first electromagnetic on-off valve 54 and the second electromagnetic on-off valve 55 Command degaussing. First
The electromagnetic on-off valve 54 is excited based on an excitation command from the controller 37B, and the second electromagnetic on-off valve 55 is
Degauss based on the degauss command from. As shown in FIG. 11, the excited first electromagnetic on-off valve 54 is connected to the main supply pipe 49.
The second solenoid valve 55, which has been demagnetized, allows the coolant to flow to the merge pipe 52 via the main supply pipe 49. Accordingly, the temperatures in the coolers 45 and 44 decrease, and the coolers 45 and 44 decrease.
The cooling action at

When the detected temperature Tx is equal to or lower than the target temperature T1, both the solenoid on-off valves 54 and 55 are demagnetized. Such control of the cooling action causes the temperature of the surface of the rotor housing 12 to converge to the target temperature T1.

The controller 37B serves as switching control means for electrically switching and controlling the electromagnetic on-off valve 54 between a supply permitting state and a supply prohibiting state. The first solenoid on-off valve 54 and the second
Electromagnetic on-off valve 55 constitutes a supply switching means.

Also in the third embodiment, the same effects as in the items (1-1) to (1-5) in the first embodiment can be obtained. The coolant supplied to the sub supply pipe 50 is the coolant after passing through the electric motor M. The temperature of the cooling liquid after passing through the electric motor M is set in a cooling area (rotor housing 12) where the cooling liquid is cooled by the supply of the cooling liquid to the sub supply pipe 50.
And the cooling action of the coolers 44 and 45 on the drive unit 33). Depending on the temperature of the electric motor M upstream of the sub supply pipe 50 with respect to the main supply pipe 49, the sub supply pipe 5
The control of dividing the supply amount of the coolant to 0 into two stages improves the appropriateness of cooling of the rotor housing 12 and the drive unit 33 that are cooled by the supply of the coolant to the sub supply pipe 50.

In the present invention, the following embodiments are also possible. (1) In the first embodiment, a cooler 45 for cooling the drive unit 33 is provided in the middle of the main supply pipe 49,
The auxiliary supply pipe 50 is branched from the main supply pipe 49 on the downstream side of 5, and an electromagnetic three-way valve 51 is interposed at the branch between the main supply pipe 49 and the auxiliary supply pipe 50. (2) In the first embodiment, the rotor housing 1
A cooler 44 for cooling the cooling unit 2 and a cooler 45 for cooling the driving unit 33 are interposed on separate sub-supply pipes, and electromagnetic three-way valves are interposed at the branches of the sub-supply pipes and the main supply pipe 49, respectively. thing. (3) The rotor housing 12 and the drive unit 33 are cooled by a single cooler. (4) In the first embodiment, the temperature of the cooler 44 is detected by the temperature detector 53. (5) The present invention is applied to a vacuum pump other than a roots pump.

[0047]

As described above in detail, according to the present invention, a main supply path arranged to cool at least one of a plurality of cooling areas and supplying a cooling liquid, A sub-supply path arranged to cool at least one of the sub-supply paths and supplying a cooling liquid from the main supply path; a supply permission state of supplying a cooling liquid to the sub-supply path side; Since the cooling device is provided with the supply switching means capable of switching to the supply prohibition state in which the cooling liquid is not supplied, the plurality of cooling regions in the vacuum pump can be appropriately cooled only by a single cooling liquid supply system. It works.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment.

FIG. 2 is a plan sectional view of the multi-stage roots pump 11;

FIG. 3A is a sectional view taken along line AA of FIG. 2; (B) is FIG.
BB sectional drawing of FIG. (C) is a sectional view taken along line CC of FIG. 2.

FIG. 4 is a sectional view taken along line DD of FIG. 1;

FIG. 5A is a control circuit diagram in a state where an electromagnetic three-way valve 51 is demagnetized. (B) is a control circuit diagram in a state where the electromagnetic three-way valve 51 is excited.

FIG. 6 is a plan view showing a second embodiment.

FIG. 7A is a control circuit diagram in a state where an electromagnetic on-off valve 54 is demagnetized. (B) is a control circuit diagram in a state where the electromagnetic on-off valve 54 is excited.

FIG. 8 is a plan view showing a third embodiment.

FIG. 9 is a control circuit diagram in a state where the electromagnetic on-off valves and 55 are demagnetized.

FIG. 10 is a control circuit diagram in a state where the electromagnetic on-off valves 54 and 55 are excited.

FIG. 11 is a control circuit diagram in a state where the electromagnetic on-off valve is excited and the electromagnetic on-off valve is demagnetized.

[Explanation of symbols]

11 Multi-stage roots pump. 12 ... A rotor housing to be a cooling area. 19, 20 ... rotating shaft. 23 to 32: rotors serving as gas transfer bodies. 37, 37A, 37B: controllers serving as switching control means. 39-43 ... Pump room. 44,4
5 ... A cooler constituting a sub-supply path. 46, 47, 48 ...
A cooler that constitutes the main supply path. 49: Main supply pipe constituting the main supply path. Reference numeral 50: a sub supply pipe constituting a sub supply path.
51 ... Electromagnetic three-way valve serving as supply switching means. 54 ... A solenoid on-off valve serving as a supply switching means. 53: Temperature detector serving as temperature detecting means. M: Electric motor.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiro Ida 2-1-1 Toyota-cho, Kariya-shi, Aichi F-term in Toyota Industries Corporation (reference) 3H003 AA05 AB06 AC01 BE06 CD01 CF04 3H029 AA06 AA09 AA16 AA22 AB06 BB12 BB51 CC07 CC09 CC12 CC22 CC48 CC56 CC82

Claims (7)

[Claims] 1. A vacuum pump for providing a suction effect by a transfer operation of a gas transfer body, wherein a main supply is provided to cool at least one of a plurality of cooling regions in the vacuum pump and supplies a cooling liquid. A path, a sub-supply path arranged to cool at least one of the plurality of cooling areas and supplying a coolant from the main supply path, and a supply to supply a coolant to the sub-supply path side Acceptable state,
A cooling device for a vacuum pump, comprising: a supply switching unit configured to switch to a supply prohibition state in which the cooling liquid is not supplied to the sub supply path side. And a switching control means for electrically switching the supply switching means between a supply permitting state and a supply prohibiting state, wherein the cooling area is cooled by a cooling liquid supplied to the sub-supply path, or A temperature detection unit that detects a temperature of the sub-supply path, wherein the switching control unit is configured to cool the cooling area with a coolant supplied to the sub-supply path based on temperature detection information of the temperature detection unit. 2. The cooling device in a vacuum pump according to claim 1, wherein the supply switching means is controlled so that the temperature of the supply pump converges to a target temperature. 3. The vacuum according to claim 2, wherein said switching control means is cooled by a cooling liquid on said main supply path, and said switching control means is upstream of said supply switching means with respect to said main supply path. Cooling device in the pump. 4. The gas transfer body is driven by an electric motor, the electric motor is cooled by a coolant on the main supply path, and the electric motor is upstream of the supply switching means with respect to the main supply path. Claim 1
A cooling device in the vacuum pump according to claim 3. 5. The vacuum pump according to claim 1, wherein a plurality of rotating shafts are arranged in parallel, a rotor is arranged on each of the rotating shafts, rotors on adjacent rotating shafts are engaged with each other, and a plurality of rotating shafts are engaged with each other. Is a multi-stage roots pump formed in a rotor housing so that a plurality of pump chambers accommodating the rotors as a set are arranged in the axial direction of the rotating shaft, and a cooling area cooled by a coolant on the sub-supply path is ,
The cooling device according to any one of claims 1 to 4, wherein the cooling device is the rotor housing that forms the pump chamber. 6. The vacuum pump according to claim 1, wherein the supply switching means is an electromagnetic three-way valve interposed at a branch between the main supply path and the sub supply path. Cooling device in. 7. The supply switching device according to claim 1, wherein the supply switching means is an electromagnetic switching valve interposed on the sub-supply path.
A cooling device in the vacuum pump according to any one of the above.