JPH10306788A - Cooling structure of vacuum pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the allowable intake pressure by cooling the inside of a pump, and prevent the increase in size, of a pump, by installing the cooling liquid holders which are almost closely kept into contact with the wall faces of a housing part, on at least a part of a cooling passage forming member. SOLUTION: A cooling passage forming member 31 which cools the inside of a pump A by flowing of the cooling liquid, is installed in a base 30. A lower cooling part 31d of the cooling passage forming member 31 comprises four cooling liquid holders 35 which are almost closely kept into contact with the upper and lower wall faces and the inner and outer peripheral wall faces of a housing part 30c, the cooling liquid holders 35 have respectively a shape obtained by dividing one ring in the circumferential direction, and are arranged at almost equal intervals. The lower faces of the cooling liquid holders 35 and the housing part 30c are close to a lower face of the base 30, an inner peripheral face of the same is close to an electromagnet 11b on the lower side of a thrust magnetic bearing 11, and further an outer peripheral face of the same is close to the bolts 28 for fastening an exhaust port casing 3b and a bottom part casing 3c. Whereby the inside of the pump A is cooled to improve the allowable intake pressure, and the increase in size, of the pump A can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure of a vacuum pump such as a turbo-molecular pump used for exhausting a vapor of a reaction product generated by reacting with a gas in an etching step in manufacturing a semiconductor. Belongs to the technical field.

[0002]

2. Description of the Related Art Generally, a vacuum pump of this type has a rotary shaft in which a rotor and a pump rotor of a motor are provided integrally at substantially a center portion and one end portion in the axial direction, respectively. A base for supporting the stator. Then, in order to rotate the rotating shaft at a high speed by the motor, heat generation of the motor increases,
The temperature rise inside the pump becomes a problem.

Therefore, conventionally, in order to suppress the temperature rise, a housing portion for housing a cooling pipe having a circular cross section as a cooling passage forming member is provided around the end of the rotating shaft opposite to the pump rotor in the base. Is provided, and the inside of the pump is cooled by flowing a cooling liquid such as cooling water through a cooling pipe in the housing portion.

[0004]

However, in the above-described conventional cooling structure, since the cooling pipe has a circular cross section,
The area of contact with the wall surface of the housing portion in the base is inevitably reduced, and even if the cross-sectional area of the cooling pipe is increased to increase the area of contact with the base, the pump becomes large. In addition, since the cooling pipe is far from the place where the motor generates heat, it is difficult to effectively cool the inside of the pump. For this reason, there is a problem that the rotating shaft cannot be rotated at a higher speed, and the allowable intake pressure of the pump cannot be improved.

[0005] The present invention has been made in view of the above points, and an object thereof is to provide a cooling structure of a vacuum pump in which the inside of the pump is cooled by a cooling passage forming member in a base. By improving the cooling structure, the contact area of the cooling passage forming member with the base is increased without increasing the size of the pump, thereby improving the cooling effect, and suppressing the temperature rise inside the pump as much as possible. The object is to improve the permissible intake pressure.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, at least a part of a cooling passage forming member is provided with a cooling liquid holder which is substantially in close contact with a wall surface of a housing portion in a base. It was provided.

More specifically, in the present invention, FIG. 1 and FIG.
As a cooling structure of a vacuum pump, a rotor (7a) of a motor (7) and a pump rotor (5) are provided at a substantially central portion and one end in an axial direction, respectively, as a cooling structure of a rotary shaft (4). A base (30) arranged around the rotating shaft (4) and supporting a stator (7b) of the motor (7); and a pump rotor (5) of the rotating shaft (4) in the base (30). ), A cooling passage forming member (31) arranged in a state housed in the housing portion (30c) for cooling the inside of the pump (A). ) Is provided at least in part with a cooling liquid holder (35) that is substantially in close contact with the wall surface of the storage section (30c).

With the above structure, the coolant holder (3)
5) can be manufactured in accordance with the shape of the empty space by avoiding necessary parts in the base (30), so that the size of the base (30) of the coolant holder (35) can be increased without increasing the size of the pump (A). ) Can be increased as compared with the case where the cooling passage forming member (31) is formed only of the cooling pipe, and the cooling effect in the pump (A) can be improved. Therefore, it is possible to suppress an increase in the temperature inside the pump (A) while preventing the pump (A) from increasing in size, and to improve the allowable intake pressure of the pump (A).

According to a second aspect of the present invention, in the first aspect of the present invention, as shown in FIGS. 1 and 2, the cooling passage forming member (31) is provided on the rotating shaft (4) on the side opposite to the pump rotor (5). A motor cooling section that extends from the end along the rotation axis (4) to the vicinity of the motor (7) and then returns along the rotation axis (4) to the end of the rotation axis (4) opposite to the pump rotor (5). (3
1a), and at least a part of the motor cooling section (31a) is substantially in close contact with the base (30).

According to the present invention, the vicinity of the motor (7) having the largest heat value can be directly cooled, so that the inside of the pump (A) can be more effectively cooled.
Therefore, the temperature rise inside the pump (A) can be more effectively suppressed, and the allowable intake pressure of the pump (A) can be further improved.

According to the third aspect of the present invention, as shown in FIGS. 3 and 4, as a cooling structure of the vacuum pump, a rotor (7a) and a pump rotor (5) of a motor (7) are provided at a substantially central portion in an axial direction and a pump rotor (5). A rotating shaft (4) provided integrally at one end with a rotation; and a base (3) arranged around the rotating shaft (4) and supporting a stator (7b) of the motor (7).
0) and a cooling passage forming member (31) arranged in the base (30) for cooling the inside of the pump (A). Motor cooling unit (31a) located on the radial side
And at least a part of the motor cooling part (31a) is substantially in close contact with the base (30). Thus, the inside of the pump (A) can be effectively cooled similarly to the invention of claim 2, and the pump (A) can be effectively cooled.
Can be improved.

According to a fourth aspect of the present invention, in the second or third aspect of the present invention, as shown in FIGS. 1 and 3, the motor cooling portion (31a) includes a portion (31) protruding outside the base (30).
c), and a lid member (37) for hermetically covering the base outer portion (31c) of the motor cooling portion (31a) with respect to the base (30) is provided.

That is, when the surface roughness of the motor cooling unit (31a) is large, vacuum leakage occurs from the inlet / outlet of the motor cooling unit of the base (30) to a portion of the base (30) communicating with the atmosphere, and the pump is pumped. Since the inside of (A) may not be able to be maintained in a vacuum, the surface roughness must be reduced. However, in the present invention, the lid member (3
Since the vacuum leak can be prevented by the method (7), even if the surface of the cooling pipe (31) becomes relatively rough, the vacuum leak can be reliably prevented. Therefore, the vacuum performance of the pump (A) can be improved while reducing the cost.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 shows an overall configuration of a turbo-molecular pump (A) as a vacuum pump having a cooling structure according to Embodiment 1 of the present invention. The turbo molecular pump (A) is used for etching a metal film of aluminum formed on the surface of a substrate using a chlorine-based gas in a vacuum atmosphere, for example, in a dry etching step in the manufacture of a semiconductor. Aluminum chloride (A
1Cl ₃ ) is used to exhaust gas molecules.

The turbo-molecular pump (A) includes a casing (3) having an intake port (1) and an exhaust port (2);
A rotating shaft (4) rotatably provided in the casing (3) and extending vertically, and a pump rotor (5) integrally rotatably provided at an upper end of the rotating shaft (4). And This turbo molecular pump (A)
Is an electric motor (7) for rotatingly driving the rotating shaft (4).
Built-in. The electric motor (7) includes a motor rotor (7a) rotatably and integrally fitted to a substantially central portion of the rotating shaft (4) in the axial direction, and a motor stator (7b) disposed on an outer peripheral side of the motor rotor (7a). ).

The casing (3) has a substantially cylindrical inner casing (3a) extending vertically and having upper and lower ends opened, and is integrally formed with an outer flange at the lower opening edge of the inner casing (3a). An exhaust port casing (3b) provided; a bottom casing (3c) provided on the lower surface of the exhaust port casing (3b) so as to cover a lower end opening of the inner casing (3a); and the exhaust port casing (3b) A cylindrical lower pump casing (3d) and an upper pump casing (3e) provided so as to vertically overlap each other, and an inlet casing (3f) provided at an upper end opening edge of the upper pump casing (3e). Consists of The intake port (1) is formed by an intake port casing (3f), while the exhaust port (2) is formed.
Is formed in the exhaust port casing (3b) so as to open toward the side (left side in FIG. 1).

The inner casing (3a), the exhaust port casing (3b) and the bottom casing (3c) of the casing (3) are arranged around the rotating shaft (4) and the stator of the electric motor (7). A base (30) for supporting (7b) is configured. The outlet casing (3b) and the bottom casing (3c) are fastened together by a plurality of bolts (28), (28),. I have.

A thrust magnetic bearing (11) is provided between the exhaust port casing (3b) and the bottom casing (3c) so as to float and hold the rotating shaft (4) rotatably in the thrust direction (vertical direction in FIG. 1). Is arranged. The magnetic bearing (11) is a disk (11) made of a magnetic material provided concentrically and integrally with the lower end of the rotating shaft (4).
a) and electromagnets (11b) and (11b) arranged close to and above the disk (11a). On the other hand, radial magnetic bearings (12) are provided at two upper and lower positions in the inner casing (3a) for floatingly holding the rotating shaft (4) so as to be rotatable in the radial direction. Each radial magnetic bearing (12) has a cylindrical portion (12a) made of a magnetic material that is rotatably and externally fitted to a rotating shaft (4).
And an electromagnet (12b) disposed close to the outer peripheral side of the cylindrical portion (12a). The electric motor (7) is arranged between the two radial magnetic bearings (12), (12). The thrust magnetic bearing (11) and the radial magnetic bearings (12) are also supported by the base (30).

Below the lower end of the rotary shaft (4), a thrust position sensor (13) for detecting the position of the rotary shaft (4) in the thrust direction, and a rotation for detecting the rotational frequency of the rotary shaft (4). And a sensor (14). Specifically, an axial target (15) is integrally provided at the lower end of the rotating shaft (2), while the axial target (15) is provided at a position facing the axis of the rotating shaft (4) of the bottom casing (3c). The position sensor (13) and the rotation sensor (14) are arranged at positions eccentric from the axis.
The bottom surface of the axial target (15) is a plane orthogonal to the axis of the rotating shaft (4), and the gap with the bottom surface is detected by a thrust position sensor (13). In addition, two concave portions (15) for detecting the rotational frequency are provided at two positions on the bottom surface of the axial target (15), which are shifted from each other by 180 °.
a) are provided, and these recesses (15) are provided.
The rotation frequency of the rotating shaft (4) is detected based on the number of times a) and (15a) pass on the rotation sensor (14).

Between the thrust magnetic bearing (11) and the lower radial magnetic bearing (12), a radial position sensor (16) for detecting the position of the lower end of the rotating shaft (4) in the radial direction is provided. Are located. Above the upper radial magnetic bearing (12), a radial position sensor (1) for detecting a position in the radial direction on the upper end side of the rotating shaft (4).
6) is arranged. Further, between the thrust magnetic bearing (11) and the lower radial position sensor (16), when the rotation of the rotating shaft (4) is abnormal, the rotating shaft (4) is connected to the electromagnets (11b) and (12b). And each position sensor (1
Two touch-down bearings (17) and (17) are provided to regulate the movement in the thrust and radial floating directions so as not to contact 3) and (16). Then, the electric motor (7) and the upper radial magnetic bearing (1)
2), one touch-down bearing (1) for similarly restricting the movement of the rotating shaft (4) in the radial floating direction.
7) is arranged.

The pump rotor (5) has a bottomed cylindrical shape with an open lower end, and is connected to the upper end of the rotating shaft (4) by bolts (18), (18),. Have been. A plurality of rotor blades (1) each provided to extend radially outward are provided in the upper half of the outer peripheral side.
9), (19),... Are arranged in multiple stages in the axial direction. On the other hand, opposed to the rotor blades (19), (19),..., A plurality of stationary members are provided on the inner peripheral side of the upper pump casing (3e) so as to extend radially inward. The blades (20), (20),... Are similarly arranged in multiple stages in the axial direction and alternately positioned with the rotor blades (19), (19),. In addition, the stationary blades (2
Spacers (21) are interposed between (0) and (20), respectively. And these rotor blades (19), (19),
, And the stationary blades (20), (20), ... constitute a turbopump.

The lower half of the outer peripheral surface of the pump rotor (5) is a cylindrical surface. On the other hand, a plurality of thread grooves (22), (22),... Are provided on the inner periphery of the lower pump casing (3d) facing the cylindrical surface.
And these cylindrical surfaces and screw grooves (22), (22),
… Constitute a screw pump.

The inner casing (3) of the base (30)
a) and between the exhaust port casing (3b) and the lower pump casing (3d), an annular annular path (23) is formed so as to go around the rotation axis (4). The annular path (23) communicates with the exhaust port (2) through a communication path (24) provided in the exhaust port casing (3b). In FIG. 1, (25) indicates electromagnets (11b), (12b) of the magnetic bearings (11) and (12),
Electric motor (7) and sensors (13), (14),
(16) and a connector for electrically connecting the power supply device and the control device (not shown).

Here, a cooling structure for cooling the inside of the turbo molecular pump (A) which is a feature of the present invention will be described.
As shown in FIG. 2, a copper cooling passage forming member (31) for cooling the inside of the pump (A) by flowing a cooling liquid (cooling water) is provided in the base (30). . Both ends of the cooling passage forming member (31) are formed of cooling pipes having a circular cross section.
3). The cooling passage forming member (31) is formed in a ring shape around the thrust magnetic bearing (11) below the base (30), that is, around the end of the rotating shaft (4) opposite to the pump rotor (5). A lower cooling portion (31d) arranged in a state accommodated in the accommodation portion (30c), and three motor cooling portions (31a) extending from the lower cooling portion (31d) to the radial side of the motor (7). , (31a),...

The lower cooling portion (31d) of the cooling passage forming member (31) is provided with four cooling liquid holders (3) which are substantially in close contact with the upper and lower wall surfaces and the inner and outer peripheral wall surfaces of the housing portion (30c).
Each of the coolant holders (35) has a shape in which one ring is divided in the circumferential direction, and is disposed at substantially equal intervals in the circumferential direction. The lower surface of each of the coolant holder (35) and the housing (30c) is the lower surface of the base (30) (the lower surface of the bottom casing (3c)).
And its inner peripheral surface to the lower electromagnet (11b) of the thrust magnetic bearing (11), and its outer peripheral surface to each bolt (28) for fastening the exhaust port casing (3b) and the bottom casing (3c). They are formed to be close to each other. That is, each of the coolant holders (35) is formed so as to be as large as possible in the lower portion inside the base (30).

Each motor cooling portion (31a) of the cooling passage forming member (31) has two cooling liquid holders (35) located near both ends of the cooling passage forming member (31).
(35) Except for each other, the cooling liquid holders (35) and (35) which are adjacent to each other are configured to be connected to each other, and each is formed of a substantially inverted U-shaped cooling pipe having a circular cross-section, And two horizontal portions (31b), (31b), and a horizontal portion (31c) connecting the upper ends of the vertical portions (31b) to each other in a substantially horizontal shape. Each motor cooling section (3
1a) extends from one coolant holder (35) along the rotating shaft (4) to the radial side of the motor (7), and then again extends along the rotating shaft (4). It is formed to return to the liquid holder (35). The vertical portions (31b) of the motor cooling portions (31a) are fitted into the cooling pipe holes (30a) provided in the inner casing (3a) of the base (30) and the exhaust port casing (3b), respectively. (30), and close to each motor cooling section (31).
The horizontal portion (31c) of (a) is located outside the base (30) and is an external portion of the base.

On the base (30), all the horizontal parts (31c), which are external parts of the motor cooling parts (31a), (31a),..., Are hermetically covered with respect to the base (30). A substantially ring-shaped lid member (37) is provided. That is, the lid member (37) and each horizontal portion (31
O-rings (39) and (40) are respectively provided between the base (30) on the inner and outer peripheral sides of (c), and the base (30) is formed by the lid member (37) and the O-rings (39) and (40). ) The upper vacuum is prevented from leaking below the base (30) from the gap between each vertical part (31b) of each motor cooling part (31a) and each cooling pipe hole (30a) of the base (30). . The lid member (37) is attached and fixed by a ring-shaped tightening nut (38) screwed into a screw portion (30b) formed on the base (30) above the lid member (37).

Each motor cooling portion (31a) of the cooling passage forming member (31) has a connecting portion (3) whose lower end portion of each vertical portion (31b) protrudes from the upper surface of each coolant holder (35).
5a) is connected to each coolant holder (35) by being inserted through an O-ring (41).
The O-rings (41) prevent the coolant from leaking from between the lower ends of the vertical portions (31b) and the connection portions (35a). An O-ring (42) is provided above each O-ring (41), that is, at a lower end of each cooling pipe hole (30a) via a collar (43). The lid member (37) (O
Ring (39), (40)) and the base (3)
0) exhaust casing (3b) and bottom casing (3
c), the vertical part (31b) of each motor cooling part (31a) and the base (3
In order to prevent the vacuum above the base (30) from completely leaking to the outside of the base (30) from the gap between each cooling pipe hole (30a) or the gap between the exhaust port casing (3b) and the bottom casing (3c). Has become.

Therefore, in the above embodiment, the electric motor (7) is controlled based on the output signal from the rotation sensor (14).
Is controlled to control the rotation frequency of the rotating shaft (4) and the pump rotor (5), and based on the output signals from the thrust position sensor (13) and each radial position sensor (16), each magnetic field is controlled. Bearing (11), (12)
The electromagnetic force of the electromagnets (11b) and (12b) is controlled so that the rotating shaft (4) is held floating. At this time, the electric motor (7) generates heat and the temperature inside the pump (A) rises. However, the lower cooling part (30d), which is a part of the cooling passage forming member (31), is provided in the housing part (30c). Four coolant holders (35), (3)
5), and each of the coolant holders (35) is formed so as to be as large as possible in the lower portion of the base (30). The contact area of the cooling passage forming member (3
1) is significantly increased as compared with the case where only the cooling pipe is provided, and the cooling effect in the pump (A) can be improved. At this time, each coolant holder (35) is connected to the base (30).
The pump (A) does not need to be large because it is disposed by effectively utilizing the empty space in the inner and lower parts.

Each motor cooling portion (31a) of the cooling passage forming member (31) is formed so as to extend to the radial side of the motor (7), and each vertical portion (31b) has a base (30). , The portion closest to the motor (7), which generates the largest amount of heat, can be directly cooled, and the inside of the pump (A) can be further effectively cooled.

Therefore, it is possible to minimize the temperature increase inside the pump (A) while preventing the pump (A) from being enlarged, and to improve the allowable intake pressure of the pump (A). Can be.

Further, a horizontal portion (31c) of the cooling passage forming member (31), which is an outer portion of the base of each motor cooling portion (31a), is covered with a cover member (37).
The vacuum above the base (30) does not leak below the base (30) from the gap between each vertical portion (31b) of the cooling passage forming member (31) and each cooling pipe hole (30a) of the base (30). Therefore, even if the surface roughness of each motor cooling portion (31a) of the cooling passage forming member (31) is large and the gap is large, the inside of the pump (A) can be completely maintained in vacuum. it can. That is, an O-ring (42) is provided at each end of each motor cooling portion (31a) of the cooling passage forming member (31), and an O-ring is provided between the exhaust casing (3b) and the bottom casing (3c). (27) are provided, respectively, and these O-rings (42),
It is incomplete to maintain the vacuum only by (27), and it is necessary to reduce the surface roughness of each motor cooling part (31a) to reduce the gap. However, the lid member (37)
The surface of each motor cooling portion (31a) can be made rough to the extent that the coolant does not leak due to the presence of the cooling water. On the other hand, the horizontal part (31c) of each motor cooling part (31a) of the cooling passage forming member (31) is extended outside the base (30), so that the base (30) is provided with each cooling pipe hole (30a). And the vertical portions (31b) of the motor cooling portions (31a) can be fitted into the holes (30a) from the pump rotor (5) side.
0) machining and motor cooling part (31a) base (3
0) can be easily assembled. Therefore, the vacuum performance of the pump (A) can be improved while reducing the cost.

In the first embodiment, each motor cooling portion (31a) of the cooling passage forming member (31) is formed so as to extend to the radial side of the motor (7). Nearby, for example, the lower radial magnetic bearing (1
Even if it is formed to extend to the side of 2), a sufficient cooling effect can be obtained. Further, the cooling passage forming member (3)
The cooling liquid holders (35), (35) are provided by a horizontal cooling pipe without providing each motor cooling section (31a) in 1).
The present invention can also be applied to a case where the cooling units are connected to each other or all of the lower cooling unit (31d) except for both ends are constituted by one cooling holder (35). That is,
Even if the cooling passage forming member (31) is provided only at the lower part of the base (30), the cooling passage forming member (3)
1) is provided with each coolant holder (35), so that the cooling effect inside the pump (A) can be enhanced only by that.

In the first embodiment, each of the coolant holders (35) has a shape in which one ring is divided in the circumferential direction and is arranged at substantially equal intervals in the circumferential direction. ) May be placed anywhere as long as there is an empty space in the base (30), and may have a shape corresponding to the empty space.

(Embodiment 2) FIG. 3 and FIG. 4 show Embodiment 2 of the present invention (in the following embodiments, the same parts as those in FIG. 1 and FIG. A detailed description is omitted, and only different points will be described), and a cooling structure for cooling the inside of the pump (A) is different from that of the first embodiment.

That is, in this embodiment, the cooling passage holder (35) is not provided in the cooling passage forming member (31), and the cooling passage forming member (31) is entirely formed of a cooling pipe having a circular cross section. A lower cooling portion (31d) formed in a substantially circular shape below the base (30);
and d) a motor cooling unit (31a) connected in the middle. Both ends of the lower cooling section (31d) are connected to a cooling liquid introduction pipe (32) and a discharge pipe (33), respectively, as in the first embodiment. The lower cooling part (31) is cut off halfway, and a connection part (31e) for connecting to the motor cooling part (31a) is formed at each end of the cut part.

The motor cooling part (31a) is a substantially circular horizontal connecting the two vertical parts (31b), (31b) extending in the vertical direction and the upper ends of the respective vertical parts (31b) substantially horizontally. (31c). The motor cooling portion (31a) extends upward from one connection portion (31e) of the lower cooling portion (31d) and extends substantially horizontally around the motor (7) on the radial side of the motor (7). , And extend downward to return to the other connecting portion (31e). The lower end of each vertical part (31b) of the motor cooling part (31a) is a lower cooling part (31d).
Are fitted into holes (31f) formed in the connection portions (31e), and O-rings (55) provided in the holes (31f) allow the holes (31f) and the respective motor cooling portions (31a) to be vertically connected. The coolant is prevented from leaking from the gap between the lower end of the portion (31b). Further, between the exhaust port casing (3b) and the bottom casing (3c) of the base (30), around the lower end of each vertical part (31b) of the motor cooling part (31a), each motor cooling part in the first embodiment described above. O-rings (56) that serve the same role as the O-rings (42) provided at the lower end of each vertical portion (31b) of the portion (31a) are provided.

Each of the vertical portions (31b) of the motor cooling portion (31a) has a base (3
0) are fitted into the cooling pipe holes (30a) provided in the inner casing (3a) and the exhaust port casing (3b), and are substantially in close contact with the base (30).
c) is located outside of the base (30) to form an outer portion of the base, and a lid member (37) for hermetically covering the horizontal portion (31c) of the base (30) is provided.

Therefore, in the second embodiment, the inside of the pump (A) is cooled mainly by the motor cooling portion (31a) of the cooling passage forming member (31). It extends to the radial side of the motor (7), each vertical portion (31b) is substantially in close contact with the base (30), and the horizontal portion (31c) is located at substantially the entire circumference on the radial side of the motor (7). As in the first embodiment, the inside of the pump (A) can be efficiently cooled. Therefore, the allowable intake pressure of the pump (A) can be improved.

[0040]

As described above, according to the first aspect of the present invention, the rotating shaft in which the rotor and the pump rotor of the motor are provided integrally at the substantially central portion and one end portion in the axial direction, respectively, A base that is disposed around and supports the stator of the motor, and is disposed around the end of the rotation shaft in the base opposite to the pump rotor, in a state housed in the housing part, to cool the pump. With respect to the cooling structure of the vacuum pump having the cooling passage forming member, at least a part of the cooling passage forming member is provided with a cooling liquid holder that is substantially in close contact with the wall surface of the housing portion.
It is possible to improve the allowable intake pressure of the pump while preventing the pump from being enlarged.

According to the second aspect of the present invention, the cooling passage forming member extends from the end of the rotating shaft opposite to the pump rotor to the vicinity of the motor along the rotating shaft, and then again extends along the rotating shaft. And a motor cooling portion that returns to the opposite end, and at least a part of the motor cooling portion is made to be substantially in close contact with the base, so that the allowable intake pressure of the pump can be further improved. it can.

According to the third aspect of the present invention, the rotor of the motor and the pump rotor are respectively provided at the substantially central portion and one end portion in the axial direction so as to be integrally rotatable with each other. As a cooling structure of a vacuum pump including a base that supports the stator and a cooling passage forming member that is disposed in the base and cools the inside of the pump, the cooling passage forming member is disposed radially laterally of the motor. Since the motor cooling unit is located and at least a part of the motor cooling unit is in close contact with the base, the same operation and effect as the second aspect of the invention can be obtained.

According to the fourth aspect of the present invention, by providing the lid member for covering the outer portion of the base of the motor cooling portion in an airtight manner with respect to the base, the cost of the pump is reduced and the vacuum performance is improved. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an overall configuration of a turbo-molecular pump as a vacuum pump having a cooling structure according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a cooling passage forming member.

FIG. 3 is a diagram corresponding to FIG. 1 in a second embodiment.

FIG. 4 is an exploded perspective view of a base showing a cooling structure according to a second embodiment.

[Explanation of symbols]

 (A) Turbo molecular pump (vacuum pump) (4) Rotary shaft (5) Pump rotor (7) Electric motor (7a) Motor rotor (7b) Motor stator (30) Base (30c) Housing (31) Cooling passage forming member (31a) Motor cooling section (31c) Horizontal section (base outside section) (35) Coolant holder (37) Lid member

Claims (4)

[Claims] 1. A rotary shaft (4) having a rotor (7a) and a pump rotor (5) of a motor (7) provided integrally at a substantially central portion and one end portion in an axial direction, respectively, and the rotary shaft (4). Base (30) arranged around the motor and supporting the stator (7b) of the motor (7)
A housing part (30c) around an end of the rotating shaft (4) opposite to the pump rotor (5) in the base (30).
And a cooling passage forming member (31) for cooling the inside of the pump (A). The cooling passage forming member (31) has at least a part thereof provided with the cooling portion (30c). A cooling structure for a vacuum pump, comprising a cooling liquid holder (35) which is substantially in close contact with a wall surface. 2. The cooling structure for a vacuum pump according to claim 1, wherein the cooling passage forming member (31) extends along the rotation shaft (4) from an end of the rotation shaft (4) opposite to the pump rotor (5). A motor cooling portion (31a) that extends to the vicinity of the motor (7) and then returns to the end of the rotating shaft (4) opposite to the pump rotor (5) along the rotating shaft (4) again. A cooling structure for a vacuum pump, wherein at least a part of the portion (31a) is substantially in close contact with the base (30). 3. A rotating shaft (4) in which a rotor (7a) and a pump rotor (5) of a motor (7) are provided integrally at a substantially central portion and one end in an axial direction, respectively, and the rotating shaft (4). Base (30) arranged around the motor and supporting the stator (7b) of the motor (7)
And a cooling passage forming member (31) arranged in the base (30) for cooling the inside of the pump (A). The cooling passage forming member (31) is arranged in a radial direction of the motor (7). A cooling structure for a vacuum pump, comprising: a motor cooling portion (31a) located on a side, wherein at least a part of the motor cooling portion (31a) is substantially in close contact with a base (30). 4. The cooling structure for a vacuum pump according to claim 2, wherein the motor cooling unit (31a) has a portion (31c) that extends outside the base (30), and the motor cooling unit (31a) ) Base outer part (31)
c) A cooling structure for a vacuum pump, wherein a cover member (37) for hermetically covering the base (30) with respect to the base (30) is provided.