VACUUM PUMP AND CONTROL APPARATUS OF VACUUM PUMP

A vacuum pump in which a pump main body and a control apparatus that controls the pump main body are integrated with each other. The control apparatus includes a cylindrical portion which protrudes from a chassis of the control apparatus and inside which a cable that connects the pump main body and the control apparatus to each other is passed. A height of the cylindrical portion exceeds a height of a gap formed between a bottom portion of the pump main body and the chassis of the control apparatus.

BACKGROUND

The present invention relates to a vacuum pump and a control apparatus of the vacuum pump and, in particular, to a vacuum pump and a control apparatus of the vacuum pump which inexpensively realizes a structure that is less likely to be infiltrated by water droplets without using a sealing material and which is equipped with a structure that enables a pump main body and the control apparatus to be readily separated and enables maintenance to be readily performed.

With recent developments in electronics, there is a rapidly growing demand for semiconductors such as memories and integrated circuits.

These semiconductors are manufactured by doping an extremely pure semiconductor substrate with an impurity to impart an electric property to the semiconductor substrate, forming a minute circuit on the semiconductor substrate by etching, or the like.

In addition, such operations must be performed inside a chamber in a high-vacuum state in order to circumvent the effect of airborne dust and the like. While vacuum pumps are generally used to exhaust the chamber, in particular, a turbo-molecular pump which is one of such vacuum pumps is frequently used from the perspectives of a small amount of residual gas, easy maintenance, and the like.

In addition, a semiconductor manufacturing process includes a large number of steps in which various process gases are caused to act on a substrate of a semiconductor, and a turbo-molecular pump is used not only to vacuumize the inside of a chamber but also to exhaust such process gases from the chamber.

The turbo-molecular pump is constituted by a pump main body and a control apparatus which controls the pump main body. In addition, conventionally, for the purpose of omitting an external cable for connecting the pump main body and the control apparatus to each other, configurations such as described in Japanese Patent Application Laid-open No. 2006-250033 and Japanese Patent Application Laid-open No. 2018-115631 are known in which a control apparatus is integrated with a side portion or a bottom portion of the pump main body.

SUMMARY

A pump main body or a semiconductor manufacturing apparatus is often provided with a cooling mechanism that utilizes water cooling. Therefore, when a control apparatus is integrated with a side portion of the pump main body, there is a risk that water droplets may infiltrate into the control apparatus in the event of a water leak or condensation around the pump main body. For this reason, the control apparatus must be equipped with a drip-proof structure and, in the case of Japanese Patent Application Laid-open No. 2006-250033, a watertight sealing material is disposed between a casing of the control apparatus and a base portion.

However, the watertight sealing material is expensive and causes an increase in cost.

In addition, the integrated pump main body and the control apparatus are sometimes separated on-site during maintenance such as when only an internal circuit is to be replaced. Therefore, a structure that enables easy separation and easy handling while providing a drip-proof structure as described above is desired.

Furthermore, when a gap6is provided between the bottom surface (lower surface) of the pump main body and a lid plate of a control unit in order to provide heat insulation between the pump main body and the control unit as described in Japanese Patent Application Laid-open No. 2018-115631, there is a risk that water droplets due to a water leak, condensation, or the like from a cooling mechanism may infiltrate into a control apparatus through the gap6when separating the control apparatus.

The present invention has been made in consideration of such conventional problems and an object thereto is to provide a vacuum pump and a control apparatus of the vacuum pump which inexpensively realizes a structure that is less likely to be infiltrated by water droplets without using a sealing material and which is equipped with a structure that enables a pump main body and the control apparatus to be readily separated and enables maintenance to be readily performed.

In order to achieve the object described above, the present invention (claim1) provides a vacuum pump in which a pump main body and a control apparatus that controls the pump main body are integrated with each other, wherein the control apparatus includes a cylindrical portion which protrudes from a chassis of the control apparatus and inside which a cable that connects the pump main body and the control apparatus to each other is passed, and a height of the cylindrical portion exceeds a height of a gap formed between a bottom portion of the pump main body and the chassis of the control apparatus.

Cooling by a water-cooled tube may cause condensation to form around the pump main body. In addition, there is a risk that water droplets may leak from the water-cooled tube during maintenance. Leaked water droplets are highly likely to infiltrate into the gap. Since the height of the cylindrical portion exceeds the height of the gap formed between the bottom portion of the pump main body and the chassis of the control apparatus, water droplets filling the gap are prevented from infiltrating from the inside of the cylindrical portion.

Accordingly, safety of circuits during maintenance work can be ensured. In addition, a drip-proof structure can be realized with a simple configuration without using a sealing material.

In addition, the present invention (claim2) is the invention of the vacuum pump, wherein the pump main body includes a relay chamber which houses a relay substrate to which an end portion of the cable is connected, and the relay chamber is provided with a detachable cover.

Removing the cover enables maintenance work in the relay chamber to be performed with ease. The pump main body and the control apparatus can be readily separated from each other by detaching the end of the cable from the relay substrate.

Furthermore, the present invention (claim3) is the invention of the vacuum pump, wherein a detachable plate that fastens the pump main body and the control apparatus to each other is provided in the bottom portion of the pump main body.

Providing the plate in the bottom portion of the pump main body enables the pump main body and the control apparatus to be integrated by simply changing the plate even when sizes of the pump main body and the control apparatus differ from each other. Therefore, for example, a single control apparatus can be freely combined with pump main bodies of different capacities. The plate is detachably fastened to the pump main body.

Furthermore, the present invention (claim4) is the invention of the vacuum pump, wherein the height of the cylindrical portion is formed so as to be higher than a combined height dimension of the gap and the plate.

The height of the cylindrical portion is formed so as to be higher than the combined height dimension of the gap and the plate. Therefore, even when water droplets land on an upper surface of the plate, the water droplets are not likely to infiltrate beyond the cylindrical portion.

Furthermore, the present invention (claim5) is the invention of the vacuum pump, wherein a base portion of the pump main body is provided with a base penetrating portion, and the height of the cylindrical portion is formed so as to be higher than a combined height dimension of the gap and the base penetrating portion.

Even when the base portion of the pump main body is provided with the base penetrating portion, by forming the height of the cylindrical portion so as to be higher than the combined height dimension of the gap and the base penetrating portion, the water droplets are not likely to infiltrate beyond the cylindrical portion.

Furthermore, the present invention (claim6) is the invention of the vacuum pump, wherein the cylindrical portion is constituted by a different member from the chassis of the control apparatus.

Furthermore, the present invention (claim7) is the invention of the vacuum pump, wherein an attachable and detachable lid is provided with respect to a side portion of the chassis of the control apparatus, the lid has a bent piece at one end thereof, and the bent piece is brought into contact with a surface of the plate.

Providing the side portion of the chassis of the control apparatus with an attachable and detachable lid enables maintenance work such as replacing a circuit board to be performed with greater ease. In addition, since the lid has a bent piece at one end thereof and the bent piece is brought into contact with the surface of the plate, water droplets are unlikely to infiltrate from between the end of the lid and the plate.

Furthermore, the present invention (claim8) is the invention of the vacuum pump, wherein an attachable and detachable lid is provided with respect to a side portion of the chassis of the control apparatus, the lid has a bent piece at one end thereof, and the bent piece is brought into contact with a surface of the base portion.

Providing the side portion of the chassis of the control apparatus with an attachable and detachable lid enables maintenance work such as replacing a circuit board to be performed with greater ease. In addition, since the lid has a bent piece at one end thereof and the bent piece is brought into contact with the surface of the base portion, water droplets are unlikely to infiltrate from between the end of the lid and the base portion.

Furthermore, the present invention (claim9) is the invention of the vacuum pump, wherein a lower end of the relay substrate does not protrude downward beyond a bottommost end of the pump main body.

Accordingly, when detaching the plate and placing the pump main body on a table, the pump main body can be placed on the table in a stable manner. A risk of damaging the relay substrate can also be reduced.

Furthermore, the present invention (claim10) is the invention of the vacuum pump, including a rotor shaft internally mounted to the pump main body and a front panel externally mounted to the control apparatus, wherein the lid is disposed within 90 degrees from a disposition direction of the front panel as viewed from a central axis of the rotor shaft.

A front side of a surface containing the front panel is often opened for convenience of operation and management. Therefore, the lid is disposed within 90 degrees from a disposition direction of the front panel as viewed from the central axis of the rotor shaft. Accordingly, an arrangement can be realized in which the lid and the cover can be readily removed without being obstructed by related apparatuses disposed around the pump main body.

Furthermore, the present invention (claim11) is a control apparatus having a chassis that is connectible to a pump main body via a predetermined gap, the control apparatus including a cylindrical portion which protrudes from the chassis and inside which a cable to be connected to the pump main body is passed, wherein a height of the cylindrical portion exceeds a height of the gap.

As described above, since the present invention (claim1) is configured such that the control apparatus includes the cylindrical portion which protrudes from the chassis of the control apparatus and inside which a cable that connects the pump main body and the control apparatus to each other is passed, and a height of the cylindrical portion exceeds a height of the gap formed between the bottom portion of the pump main body and the chassis of the control apparatus, water droplets filling the gap are prevented from infiltrating from the inside of the cylindrical portion.

Accordingly, safety of circuits during maintenance work can be ensured. In addition, a drip-proof structure can be realized with a simple configuration without using a sealing material.

DETAILED DESCRIPTION

Hereinafter, an embodiment of the present invention will be described.FIG. 1shows a configuration diagram of the embodiment of the present invention. InFIG. 1, in a turbo-molecular pump10, a pump main body100and a control apparatus200are integrated.

An inlet port101is formed at an upper end of a cylindrical outer casing127of the pump main body100. A rotating body103in which a plurality of rotor blades102a,102b,102c,. . . constituted by turbine blades for sucking and exhausting gas are radially formed in multiple stages in a circumferential portion inside the outer casing127.

A rotor shaft113is mounted to a center of the rotating body103and, for example, a so-called five-axis control magnetic bearing levitates and supports the rotor shaft113in midair and controls a position of the rotor shaft113.

As an upper radial electromagnet104, four electromagnets are arranged so as to form pairs along mutually orthogonal X and Y axes which are coordinate axes in a radial direction of the rotor shaft113. An upper radial sensor107constituted by four electromagnets is provided in proximity to and in correspondence with the upper radial electromagnet104. The upper radial sensor107is configured to detect a radial displacement of the rotating body103and to send the detected radial displacement to the control apparatus200.

In the control apparatus200, based on a displacement signal detected by the upper radial sensor107, excitation of the upper radial electromagnet104is controlled via a compensation circuit having a PID adjustment function and a position in the radial direction of an upper side of the rotor shaft113is adjusted.

The rotor shaft113is formed of a high magnetic permeability material (such as iron) or the like and is configured so as to be attracted by a magnetic force of the upper radial electromagnet104. The adjustment described above is respectively independently performed in an X axis direction and a Y axis direction.

In addition, a lower radial electromagnet105and a lower radial sensor108are arranged in a similar manner to the upper radial electromagnet104and the upper radial sensor107and adjust a position in the radial direction of a lower side of the rotor shaft113in a similar manner to the position in the radial direction of the upper side.

Furthermore, axial electromagnets106A and106B are arranged so as to vertically sandwich a disc-shaped metal disk111provided in a lower part of the rotor shaft113. The metal disk111is constituted by a high magnetic permeability material such as iron. An axial sensor109is provided in order to detect an axial displacement of the rotor shaft113, and the axial sensor109is configured such that an axial displacement signal thereof is sent to the control apparatus200.

The axial electromagnets106A and106B are configured so that excitation thereof is controlled based on the axial displacement signal via the compensation circuit having a PID adjustment function of the control apparatus200. The axial electromagnet106A and the axial electromagnet106B respectively attract the metal disk111upward and downward by magnetic force.

As described above, the control apparatus200is configured to appropriately adjust magnetic forces exerted on the metal disk111by the axial electromagnets106A and106B to magnetically levitate the rotor shaft113in the axial direction and hold the rotor shaft113in space in a contactless manner.

A motor121includes a plurality of magnetic poles circumferentially arranged so as to surround the rotor shaft113. Each magnetic pole is controlled by the control apparatus200so as to rotationally drive the rotor shaft113via an electromagnetic force which acts between the magnetic pole and the rotor shaft113.

A plurality of stator blades123a,123b,123c,. . . are disposed across small gaps from the rotor blades102a,102b,102c,. . . . The rotor blades102a,102b,102c,. . . are formed inclined by a prescribed angle relative to a plane perpendicular to an axial line of the rotor shaft113in order to respectively transport a molecule of exhaust gas downward when the exhaust gas collides.

In addition, the stator blade123is also formed inclined by a prescribed angle relative to a plane perpendicular to the axial line of the rotor shaft113and is disposed so as to alternate with the stages of the rotor blade102toward inside of the outer casing127.

Furthermore, an end of the stator blade123is supported in a state of being fitted and inserted between a plurality of stacked stator blade spacers125a,125b,125c,. . .

The stator blade spacer125is a ring-shaped member constituted by, for example, a metal such as aluminum, iron, stainless steel, or copper or a metal such as an alloy containing these metals as components.

The outer casing127is fixed across a small gap in an outer circumference of the stator blade spacer125. A base portion129is disposed in a bottom portion of the outer casing127, and a threaded spacer131is disposed between a lower portion of the stator blade spacer125and the base portion129. In addition, an outlet port133which communicates with the outside is formed in a lower portion of the threaded spacer131in the base portion129.

The threaded spacer131is a cylindrical member constituted by a metal such as aluminum, copper, stainless steel, or iron or a metal such as an alloy containing these metals as components, and a spiral thread groove131ais engraved in plurality on an inner circumferential surface of the threaded spacer131.

A direction of the spirals of the thread grooves131ais a direction in which, when a molecule of exhaust gas moves in a direction of rotation of the rotating body103, the molecule is transported toward the outlet port133.

A rotor blade102dis suspended from a lowermost portion which continues from the rotor blades102a,102b,102c,. . . of the rotating body103. An outer circumferential surface of the rotor blade102dis cylindrical in shape and overhangs toward the inner circumferential surface of the threaded spacer131, and is in proximity to the inner circumferential surface of the threaded spacer131across a prescribed gap.

The base portion129is a disc-shaped member constituting a base of the turbo-molecular pump10and is generally constituted by a metal such as iron, aluminum, or stainless steel.

Since the base portion129physically holds the turbo-molecular pump10and also has a function of a heat conductive path, a metal having both rigidity and high thermal conductivity such as iron, aluminum, or copper is desirably used.

In the configuration described above, when the rotor blade102is driven by the motor121and rotates together with the rotor shaft113, exhaust gas from the chamber is sucked through the inlet port101due to actions of the rotor blade102and the stator blade123.

The exhaust gas sucked from the inlet port101passes between the rotor blade102and the stator blade123and is transported to the base portion129. At this point, while a temperature of the rotor blade102rises due to frictional heat generated when the exhaust gas comes into contact or collides with the rotor blade102, conduction or radiation of heat generated in the motor121, or the like, this heat is transferred to the side of the stator blade123by radiation, conduction by a gas molecule of the exhaust gas, or the like.

The stator blade spacers125are joined to one another in an outer circumferential portion and transfers heat received by the stator blade123from the rotor blade102, frictional heat generated when the exhaust gas comes into contact or collides with the stator blade123, or the like to the outer casing127and the threaded spacer131.

The exhaust gas transported to the threaded spacer131is sent to the outlet port133while being guided by the thread grooves131a.

In some cases, process gases are introduced in a high-temperature state into a chamber in order to enhance reactivity. In addition, once the process gases are cooled and a temperature thereof drops to a certain level when exhausted, the process gases may solidify and cause a product to be deposited in an exhaust system.

Furthermore, a process gas of this type may cool and solidify inside the turbo-molecular pump10and adhere to and accumulate on the interior of the turbo-molecular pump10.

When a deposit of a process gas accumulates inside the turbo-molecular pump10, the deposit may narrow a pump flow path and cause a decline in performance of the turbo-molecular pump10.

When a temperature near the outlet port is low, the product described above readily solidifies and adheres particularly near the rotor blade102dand the threaded spacer131. In order to solve this problem, conventionally, a heater or an annular water-cooled tube (not shown) is wound around an outer circumference of the base portion129or the like and, for example, a temperature sensor (such as a thermistor) (not shown) is embedded in the base portion129, whereby heating by the heater or cooling by the water-cooled tube is controlled so as to keep the temperature of the base portion129at a constant high temperature (set temperature) based on a signal from the temperature sensor.

Next, a structure around terminals to which a control cable and a power cable are to be connected between the pump main body100and the control apparatus200will be described.FIG. 2is an enlarged view of a structural portion around the terminal inFIG. 1.

InFIGS. 1 and 2, a plate150for aligning fixed positions with the control apparatus200is attached to a bottom portion of the base portion129. A relay chamber201is formed in the base portion129, and the relay chamber201is provided with an attachable and detachable cover203. A space205which connects to the relay chamber201and which is to be used for wiring of a magnetic bearing, a motor, and the like inside the pump main body100is formed inside the base portion129. The space205is hermetically sealed by a hermetic connector207(to be described later) and is therefore filled with a vacuum atmosphere but, on the other hand, the control apparatus200and the relay chamber201are filled with an air atmosphere.

In addition, the hermetic connector207is mounted to a wall portion around a right end of the space205. A large number of pins209penetrate the hermetic connector207. A right end of the pin209is exposed and penetrates a small hole (not shown) of a relay substrate211. The pin209is soldered at the small hole portion of the relay substrate211with respect to the relay substrate211which provides connection to the control apparatus200.

A terminal213is disposed at a lower end of the relay substrate211and configured such that one end of a harness215is attachable and detachable to and from the terminal213.

A hole150athat connects to the relay chamber201is formed in the plate150, and a hole200ais formed in a portion of a ceiling wall (chassis) of the control apparatus200which faces the hole150a.A depressed portion200bis formed in an upper circumference of the hole200aof the control apparatus200, and a hollow plate-like portion221aformed in a bottom portion of a cylindrical member221is fixed by a bolt (not illustrated) to the depressed portion200b.The cylindrical member221penetrates the hole150a,and a height of the cylindrical member221is formed higher than an upper surface of the plate150. The cylindrical member221corresponds to the cylindrical portion, and a horizontal sectional shape of the cylindrical member221may be any shape including an ellipse or a rectangle.

Another end of the harness215passes through the cylindrical member221and the hole200a,extends into the control apparatus200, and connected to a terminal of a circuit board217disposed inside the control apparatus200.

On the other hand, a control cable and a power cable (not shown) are connected to a left end of the pin209and passed inside the space205.

An attachable and detachable lid219is disposed in a right-side portion of a chassis that forms the control apparatus200. A bent piece219ahaving been bent in an L-shape is provided at an upper end of the lid219so as to protrude outward. The lid219is screwed to a right end of the chassis of the control apparatus200, and the bent piece219ais brought into contact with a lower surface of the plate150.

A gap220of around 1 mm is formed to provide heat insulation between the plate150and the control apparatus200. A bottom portion wall of the control apparatus200and the plate150are fixed by hexagon head bolt columns (not illustrated) having been erected at four corners of the control apparatus200. The gap220is secured by a height of the hexagon head bolt columns

Next, an action of the embodiment of the present invention will be described.

Disposing the plate150in the bottom portion of the pump main body100enables the pump main body100and the control apparatus200to be integrated by simply changing the plate150even when sizes of the pump main body100and the control apparatus200differ from each other. Therefore, for example, a single control apparatus200can be freely combined with pump main bodies100of different capacities. The plate150is detachably fastened to the pump main body100by bolts.

A configuration can be adopted in which the lower end of the relay substrate211is extended downward so as to penetrate the inside of the cylindrical member221. However, with the configuration in which the lower end of the relay substrate211is extended downward, for example, when removing the plate150and placing the pump main body100on a table during an operation to attach and detach the pump main body100and the control apparatus200, the lower end portion of the relay substrate211not only comes into contact with the table first and prevents the pump main body100from being placed on the table in a stable manner but may also damage the relay substrate211.

In consideration thereof, desirably, the lower end of the relay substrate211does not protrude in an axial direction beyond the upper surface of the plate150or the bottom surface of the pump main body100.

Cooling by a water-cooled tube may cause condensation to form around the base portion129. In addition, there is a risk that water droplets may leak from the water-cooled tube during maintenance. Leaked water droplets are highly likely to infiltrate into the gap220. In particular, when the lid219has been removed, the likelihood of infiltration by water droplets further increases. In this case, while the water droplets are likely to flow into the depressed portion200b,since the hollow plate-like portion221aand the depressed portion200bare hermetically fixed to each other by respective metal surfaces with bolts (not illustrated), water droplets are unlikely to infiltrate into the control apparatus200.

Furthermore, a greater hermetic effect is exhibited by increasing respective flatnesses of the bottom surface of the hollow plate-like portion221aand the depressed portion200b.

In addition, in case water droplets infiltrate the gap220, an incline may be provided in a direction perpendicular to the lid219in order to produce a drainage effect.

In addition, since the cylindrical member221penetrates the gap220and is formed higher than the thickness of the gap220, water droplets that fill the gap220are prevented from infiltrating from inside the cylindrical member221. Furthermore, even when water droplets land on the upper surface of the plate150, since the cylindrical member221is provided so as to protrude higher than the upper surface of the plate150, the water droplets are not likely to infiltrate beyond the cylindrical member221.

In addition, since the bent piece219ahaving been bent in an L-shape is provided so as to protrude outward at an upper end of the lid219on a side of the pump main body100, water droplets are unlikely to infiltrate into the control apparatus200. Furthermore, since the bent piece219aand the plate150are hermetically fixed to each other by respective metal surfaces with bolts (not illustrated), water droplets are also unlikely to infiltrate from between the upper end of the lid219and the plate150. Moreover, as will be described later, even in a configuration in which the base portion129is deformed without providing the plate150, a similar effect can be obtained by bringing the bent piece219ainto contact with the bottom surface of the base portion129.

As described above, a drip-proof structure can be inexpensively realized by a component configuration solely based on metal working such as sheet metal pressing and without the use of a sealing material. In addition, an operation to attach and detach the harness215by removing the cover203can be readily performed while providing a drip-proof function. Accordingly, the control apparatus200can be readily detached. Furthermore, even during on-site maintenance work, work such as replacing a circuit board inside the control apparatus200can be readily performed by opening the lid219while providing a drip-proof function.

In the embodiment of the present invention, the plate150is described as a member that is independent from the pump main body100. However, as represented by another embodiment shown inFIG. 3, the base portion129of the pump main body100is deformed without providing the plate150as a separate member. In addition, the plate150may be disposed with respect to the pump main body100as a base bottom portion151. In this case, in a similar manner to a case where the plate150is interposed, a bottom portion wall of the control apparatus200and the base bottom portion151are fixed by hexagon head bolt columns (not illustrated) having been erected at four corners of the control apparatus200. Furthermore, the gap220is secured by the height of the hexagon head bolt columns. In addition, the base bottom portion151is provided with a base penetrating portion151athat connects to the relay chamber201.

It should be noted that, inFIG. 3, elements that are the same as those inFIG. 1will be denoted by same reference signs and descriptions thereof will be omitted.

In this case, the lower end of the relay substrate211desirably ends on an inner side of the pump instead of an upper surface of the base penetrating portion151ain a similar manner to that described earlier.

Furthermore, while the cylindrical member221is configured as an independent member in the embodiment of the present invention, as represented by another embodiment shown inFIG. 4, a cylindrical portion231may be provided so as to protrude from the ceiling wall of the control apparatus200. A horizontal sectional shape of the cylindrical portion231may be any shape including an ellipse or a rectangle. It should be noted that, inFIG. 4, elements that are the same as those inFIG. 1will be denoted by same reference signs and descriptions thereof will be omitted.

In this case, the ceiling wall and the cylindrical portion231are integrally formed. WhileFIG. 4shows an example in which the plate150is not provided but integrally formed with the pump main body100as the base bottom portion151of the pump main body100in a similar manner toFIG. 3, alternatively, a configuration may be adopted in which the plate150being a member that is independent from the pump main body100is provided in a similar manner toFIGS. 1 and 2.

Next, a suitable arrangement method of the relay chamber201, the lid219, and the cover203will be described.

Generally, various apparatuses and equipment260such as a power supply and piping are arranged around a chamber of a semiconductor manufacturing apparatus. In such an environment, the turbo-molecular pump10is often suspended in a lower part of the chamber. In such a case, for example, as shown inFIG. 5, a situation may occur in which surfaces other than a surface provided with a panel (a front panel250) on which a power supply switch, a connector for connecting to the power supply, a cable connector for communication with the semiconductor manufacturing apparatus, and the like of the control apparatus200are concentrated are surrounded by the apparatuses and equipment260. This is because at least a front side of the surface containing the front panel250needs to be opened for convenience of operation and management.

In such a case, in order to replace a circuit component on-site, desirably, only the control apparatus200is attachable and detachable in a state where the pump main body100is suspended in the lower part of the chamber. In addition, to this end, desirably, the lid219and the cover203are arranged so as to be readily removable without being obstructed by the apparatuses and equipment260. As shown inFIG. 6, the control apparatus200can be readily pulled out toward a front side that is a disposition direction of the front panel250relative to the apparatuses and equipment260.

In this case, by disposing the relay chamber201, the lid219, and the cover203at positions close to the surface of the front panel250of the control apparatus200, a worker can access the relay chamber201, the lid219, and the cover203from an opened portion and on-site maintenance work can be readily performed. In other words, as shown inFIG. 6, when taking ease of maintenance work into consideration, an angle α formed between a disposition direction L1of the relay chamber201, the lid219, and the cover203and a disposition direction L2of the front panel250as viewed from a center point O of the rotor shaft113of the turbo-molecular pump10is desirably within 90 degrees.

Moreover, it will be obvious to those skilled in the art that various changes and modifications may be made and embodiments may be combined without departing from the spirit of the present invention and that the present invention also encompasses such changes and modifications.