Abstract:
A vacuum pump casing has an opening that is covered and sealed by a cover member. The cover member is formed of molded resin with connector pins molded therein. The connector pins project outwardly from opposite sides of the cover member and are connected outside the pump casing to cables leading to a control device and connected inside the pump casing to cables leading to components within the pump casing.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   The present application is a division of application Ser. No. 11/448,196, filed Jun. 7, 2006 and now U.S. Pat. No. 7,393,228, and priority thereto for common subject matter is hereby claimed. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a terminal structure and a vacuum pump, and in particular, to a terminal structure capable of preventing damage due to an excessive force and having high sealing property, and a vacuum pump to which the terminal structure is applied. 
   2. Description of the Related Art 
   As a result of recent developments in electronics, there is a rapidly increasing demand for semiconductor devices such as memories and integrated circuits. 
   Such semiconductor devices are manufactured by doping semiconductor substrates of a very high purity with impurities to impart electrical properties thereto, by forming minute circuits on the semiconductor substrates through etching, etc. 
   In order to avoid the influences of dust in the air, etc., such operations must be conducted in a chamber in a high vacuum state. To evacuate this chamber, a vacuum pump is generally used; in particular, a turbo molecular pump, which is a kind of vacuum pump, is widely used since it allows maintenance with ease, etc. 
   Further, a semiconductor manufacturing process involves a number of steps of causing various process gasses to act on a semiconductor substrate, and the turbo molecular pump is used not only to create a vacuum in the chamber but also to evacuate such process gases from the chamber. 
   Further, in an equipment such as an electron microscope, a turbo molecular pump is used to create a high vacuum state within the chamber of the electron microscope, etc. in order to prevent refraction, etc. of the electron beam due to the presence of dust or the like. 
   Further, such a turbo molecular pump is composed of a turbo molecular pump main body for sucking gas from the chamber of a semiconductor manufacturing apparatus, the electron microscope, or the like, and a control device for controlling the turbo molecular pump main body. 
     FIG. 5  shows a longitudinal sectional view of the turbo molecular pump main body. 
   In  FIG. 5 , a turbo molecular pump main body  100  has an inlet port  101  formed at the upper end of an outer cylinder  127 . On an inner side of the outer cylinder  127 , there is provided a rotor  103  in a periphery of which there are formed radially and in a number of stages a plurality of rotary vanes  102   a ,  102   b ,  102   c , . . . formed of turbine blades for sucking and evacuating gases. 
   Mounted at a center of this rotor  103  is a rotor shaft  113 , which is levitatingly supported and position-controlled by, for example, a so-called 5-axis control magnetic bearing. 
   Upper radial electromagnets  104  are four electromagnets arranged in pairs in an X-axis and an Y-axis. In close proximity to and in correspondence with the upper radial electromagnets  104 , there are provided four upper radial sensors  107 . The upper radial sensors  107  detect radial displacement of the rotor  103 , and transmit displacement signals to a control device  200 . 
   Based on the displacement signals detected by the upper radial sensors  107 , the control device  200  controls the excitation of the upper radial electromagnets  104  by an output of an amplifier transmitted through a magnetic bearing control circuit having a PID adjustment function, and adjusts the radial position of an upper side of the rotor shaft  113 . Here, the magnetic bearing control circuit converts analog sensor signals representing the displacement of the rotor shaft  113  detected by the upper radial sensors  107  into digital signals by an A/D converter, and processes the signals to adjust electric current caused to flow through the upper radial electromagnets  104 , levitating the rotor shaft  113 . 
   Further, to perform fine adjustment on the electric current caused to flow through the upper radial electromagnets  104 , the electric current caused to flow through the upper radial electromagnets  104  is measured, and fed back to the magnetic bearing control circuit. 
   The rotor shaft  113  is formed of a high magnetic permeability material (such as iron), and is attracted by the magnetic force of the upper radial electromagnets  104 . Such adjustment is effected independently in the X-axis and the Y-axis directions. 
   Further, lower radial electromagnets  105  and lower radial sensors  108  are arranged in the same way as the upper radial electromagnets  104  and the upper radial sensors  107 , and the lower radial position of the of the rotor shaft  113  is adjusted by the control device  200  in the same manner as the upper radial position thereof. 
   Further, axial electromagnets  106 A and  106 B are arranged so as to sandwich from above and below a circular metal disc  111  provided in a lower portion of the rotor shaft  113 . The metal disc  111  is formed of a high magnetic-permeability material, such as iron. There are provided axial sensors  109  for detecting an axial displacement of the rotor shaft  113 . Axial displacement signals obtained through detection by the axial sensors  109  are transmitted to the control device  200 . 
   Based on the axial displacement signals, the axial electromagnets  106 A and  106 B are excited and controlled by the output of the amplifier transmitted through the magnetic bearing control circuit with a PID adjustment function of the control device  200 . The axial electromagnets  106 A attract the metal disc  111  upwards by the magnetic force, and the axial electromagnets  106 B attract the metal disc  111  downwards. 
   In this way, the control device  200  appropriately adjusts the magnetic forces exerted on the metal disc  111  by the axial electromagnets  106 A and  106 B, and magnetically levitates the rotor shaft  113  in the axial direction, retaining it in the air in a non-contact fashion. 
   A motor  121  is equipped with a plurality of magnetic poles circumferentially arranged so as to surround the rotor shaft  113 . Each of these magnetic poles is controlled so as to rotate and drive the motor  121  by a power signal output from a drive circuit and transmitted through a motor control circuit with a PWM control function of the control device  200 . 
   Further, the motor  121  is equipped with an RPM sensor and a motor temperature detecting sensor (not shown). The RPM of the rotor shaft  113  is controlled by the control device  200  on the basis of detection signals received from the RPM sensor and the motor temperature detecting sensor. 
   There are arranged a plurality of stationary vanes  123   a ,  123   b ,  123   c , . . . , with a slight gap being between them and the rotary vanes  102   a ,  102   b ,  102   c , . . . , respectively. In order to downwardly transfer the molecules of the exhaust gas through collision, the rotary vanes  102   a ,  102   b ,  102   c , . . . are inclined by a predetermined angle with respect to planes perpendicular to the axis of the rotor shaft  113 . 
   Further, the stationary vanes  123  are inclined by a predetermined angle with respect to planes perpendicular to the axis of the rotor shaft  113 , and are arranged so as to protrude toward the interior of the outer cylinder  127  and in alternate stages with the rotary vanes  102 . 
   Further, one ends of the stationary vanes  123  are supported while being inserted between a plurality of stationary vane spacers  125   a ,  125   b ,  125   c , . . . stacked together. 
   The stationary vane spacers  125  are ring-like members formed of a metal, such as aluminum, iron, stainless steel, or copper, or a metal such as an alloy containing those metals as the components. 
   Further, in an outer periphery of the stationary vane spacers  125 , the outer cylinder  127  is fixed in position with a slight gap therebetween. A base portion  129  is provided at a bottom portion of the outer cylinder  127 . Between the lower portion of the stationary vanes pacers  125  and the base portion  129 , there is provided a threaded spacer  131 . In the portion of the base portion  129  which is below the threaded spacer  131 , there is formed an exhaust port  133 , which communicates with the exterior. 
   The threaded spacer  131  is a cylindrical member formed of a metal, such as aluminum, copper, stainless steel, or iron, or a metal such as an alloy containing those metals as the components, and has in an inner peripheral surface thereof a plurality of spiral thread grooves  131   a  formed. 
   The spiral direction of the thread grooves  131   a  is a direction in which, when the molecules of the exhaust gas move in the rotating direction of the rotor  103 , these molecules are transferred toward the exhaust port  133 . 
   In the lowermost portion of the rotor  103  connected to the rotary vanes  102   a ,  102   b ,  102   c , . . . , there is provided a rotary vane  102   d  vertically downwards. The rotary vane  102   d  has an outer peripheral surface of a cylindrical shape, protrudes toward the inner peripheral surface of the threaded spacer  131 , and is placed in close proximity to the threaded spacer  131  with a predetermined gap therebetween. 
   Further, the base portion  129  is a disc-like member constituting a base portion of the turbo molecular pump main body  100 , and is generally formed of a metal, such as iron, aluminum, or stainless steel. 
   The base portion  129  physically retains the turbo molecular pump main body  100 , and also functions as a heat conduction path, so it is desirable to use a metal that is rigid and of high heat conductivity, such as iron, aluminum, or copper, for the base portion  129 . 
   Further, a connector  160  is arranged on the base portion  129 . The connector  160  serves as an outlet for signal lines between the turbo molecular pump main body  100  and the control device  200 . The turbo molecular pump main body  100  side portion of the connector  160  is formed as a male terminal and the control device  200  side portion thereof is formed as a female terminal. Further, the connector  160  has a seal structure, which is detachable, and capable of maintaining a vacuum inside the turbo molecular pump main body  100 . 
   When, with this construction, the rotary vanes  102  are driven by the motor  121  and rotate together with the rotor shaft  113 , an exhaust gas is sucked from a chamber through the inlet port  101  by the action of the rotary vanes  102  and the stationary vanes  123 . 
   Then, the exhaust gas sucked in through the inlet port  101  flows between the rotary vanes  102  and the stationary vanes  123  to be transferred to the base portion  129 . The exhaust gas transferred to the base portion  129  is sent to the exhaust port  133  while being guided by the thread grooves  131   a  of the threaded spacer  131 . 
   In the above-described example, the threaded spacer  131  is provided in the outer periphery of the rotary vane  102   d , and the thread grooves  131   a  are formed in the inner peripheral surface of the threaded spacer  131 . However, conversely to the above, the thread grooves may be formed in the outer peripheral surface of the rotary vane  102   d , and a spacer with a cylindrical inner peripheral surface may be arranged in the periphery thereof. 
   Further, in order that the gas sucked in through the inlet port  101  may not enter the electrical section formed of the motor  121 , the lower radial electromagnets  105 , the lower radial sensors  108 , the upper radial electromagnets  104 , the upper radial sensors  107 , etc., a predetermined pressure is maintained with a purge gas. 
   For this purpose, piping (not shown) is arranged in the base portion  129 , and the purge gas is introduced through the piping. The purge gas thus introduced flows through the gaps between a protective bearing  120  and the rotor shaft  113 , between a rotor and stator of the motor  121 , and between a stator column  122  and the rotary vanes  102  before being transmitted to the exhaust port  133 . 
   While the turbo molecular pump main body  100  and the control device  200  are usually formed as separate components, they are, in some cases, integrated with each other for a space saving as shown in JP 10-103288 A and JP 11-173293 A. 
     FIG. 6  shows an example in which the turbo molecular pump main body  100  and the control device  200  are not separated but integrated with each other. In this case, cables  161  are attached to the connector  160  on the turbo molecular pump main body  100  side. A connector  260  is arranged at the other end of the cables  161  so as to be detachable with respect to the control device  200 . The connector  160  and the connector  260  respectively protrude from the side portion of the turbo molecular pump main body  100  and the control device  200 , with the cables in a bundle extending between the connectors. 
   In a 5-axis control magnetic bearing, the number of cables is 30 or more, so a large size vacuum connector is required. The cables are thick, and their bending radius is large. However, they are flexible to a certain degree, so they are not easily damaged or the like by an excessive force applied at the time of assembly. On the other hand, they involve a problem in terms of space. 
   In another example of the arrangement in which the turbo molecular pump main body and the control device are integrated with each other, instead of exposing the cables outside the turbo molecular pump main body  100  and the control device  200  as shown in  FIG. 6 , it is possible, as shown in  FIG. 7 , to directly connect a male connector  165  protruding from a turbo molecular pump main body  110  with a female connector  265  protruding from a control device  210 . 
   In this connection, the male connector  165  is a vacuum connector, and is fastened to the turbo molecular pump main body  110  by bolts  167 . The female connector  265  is similarly fastened to the control device  210  by bolts  169 . Further, a plurality of spacers  171  are provided between the turbo molecular pump main body  110  and the control device  210 . The spacers  171  are formed as hollow cylinders, and bolts  173  are passed through them so as to fix the turbo molecular pump main body  110  and the control device  210  to each other through the intermediation of the spacers  171 . 
   In this way, the male connector  165  is fastened to the turbo molecular pump main body  110  by the bolts, and the female connector  265  is fastened to the control device  210  by the bolts, so, when, for example, the control device  210  is inserted obliquely to attach it to the turbo molecular pump main body  110 , an excessive force may be exerted between the male connector  165  and the female connector  265 , resulting in damage of the connectors. 
   SUMMARY OF THE INVENTION 
   The present invention has been made in view of the above problems in the prior art. It is an object of the present invention to provide a terminal structure capable of preventing damage due to an excessive force and having high sealing property, and a vacuum pump to which the terminal structure is applied. 
   Therefore, a terminal structure of the present invention is constructed by including: a first connector; a first member having the first connector; a second connector electrically connected by being fit-engaged with the first connector; a second member having the second connector; and elastic retaining means for elastically retaining the first connector with respect to the first member, and/or elastically retaining the second connector with respect to the second member. 
   Even when the first connector is inserted somewhat obliquely with respect to the second connector, and an excessive force is exerted between the connectors, it is possible to mitigate the force through the elastic force of the elastic retaining means. Thus, there is no fear of the connectors suffering damage. Further, there is little fear of an electrical short-circuiting, a leakage of current, etc. 
   Further, the terminal structure of the present invention is constructed by including movement regulating means for effecting regulation to prevent a distance through which the fit-engagement is effected from exceeding a predetermined length. 
   Due to this regulation, the tension of the elastic force due to the elastic retaining means is maintained at an appropriate level. Thus, it is possible to obtain an appropriate rigidity at the time of fit-engagement and to reliably maintain the connection between the pins. 
   Further, the present invention relates to a vacuum pump, characterized in that the first member is applied to a vacuum pump main body, and the second member is applied to a control device. 
   It is desirable for the vacuum pump main body and the control device to be integrated with each other. Even when the control device is inserted somewhat obliquely with respect to the vacuum pump main body, and an excessive force is exerted between the connectors, it is possible to mitigate the force by the elastic retaining means, so there is no fear of the connectors suffering damage. Thus, there is little fear of a gas leakage occurring from the vacuum pump main body to cause a pump heating, an electrical short-circuiting, a leakage of current, etc., thereby achieving an improvement in terms of the reliability of the pump. 
   Still further, the vacuum pump of the present invention is constructed by including: at least one cable whose conductor is exposed at a portion between both ends of the cable; a molding member formed through solidification-molding with at least the exposed conductor portion of the cable included; and an outer cylinder to or with which the molding member is mounted or integrated. 
   It is desirable for the vacuum pump main body and the control device to be integrated with each other. The cable is molded with a resin or the like with the conductor exposed, so it is possible to prevent the gas leakage through a gap between the conductor and the cable covering. Thus, it is possible to effect a vacuum seal without using a large vacuum connector. Further, it is possible to realize a space saving and a reduction in cost. The pump and the control circuit are connected to each other by the cable, so even if an excessive force is applied, the cable simply deflects, and there is no fear of the connectors suffering damage. Thus, there is little fear of a gas leakage occurring from the vacuum pump main body to cause a pump heating, an electrical short-circuiting, a leakage of current, etc., thereby achieving an improvement in terms of the reliability of the pump. 
   Yet further, the vacuum pump of the present invention is constructed by including: at least one pin with conductivity; cable conductor fixing means arranged at both ends of the pin and allowing conductors of cables fixed to the pin; a molding member formed through solidification-molding with the pin included; and an outer cylinder to or with which the molding member is mounted or integrated. 
   It is desirable for the vacuum pump main body and the control device to be integrated with each other. A molding member composed of a resin or the like is solidification-molded with the pin included. Thus, there is no gap between the molding member and the pin, maintaining a vacuum seal therebetween. When the molding member is mounted to the outer cylinder, it is desirable to arrange a seal member, such as an O-ring, between the molding member and the outer cylinder. With this arrangement, it is possible to effect a vacuum seal without using a large vacuum connector, and it is possible to realize a space saving and a reduction in cost. 
   The cable conductor fixing means may be soldered, press-fitted, etc. after forming elongated holes at both ends of the pin and passing the cable cores therethrough. Thus, the operation involved is simple. The pump and the control circuit are connected to each other by the cable, so even if an excessive force is applied, the cable simply deflects, and there is no fear of the connector suffering damage. Thus, there is little fear of an electrical short-circuiting, a leakage of current, etc., thereby achieving an improvement in terms of the reliability of the pump. An end portion of the cable entering the control device can be connected to a miniature terminal or directly connected to the board, etc., whereby a space saving is achieved, and the mounting is easy to perform. 
   Further, the vacuum pump of the present invention is characterized in that: a control device is provided side by side with the outer cylinder; a cable inside the outer cylinder and a cable inside the control device are electrically connected through the molding member; and the solidification-molded portion of the molding member and at least one of the portion of the molding member mounted to the outer cylinder, and the portion of the molding member integrated with the outer cylinder, are formed as seals. 
   By arranging the outer cylinder and the control device side by side, the apparatus as a whole is made compact. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
       FIG. 1  is a schematic view of a terminal structure according to a first embodiment of the present invention; 
       FIG. 2  is a diagram showing a state in which connectors are connected with each other; 
       FIG. 3  is a schematic sectional view of a second embodiment of the present invention; 
       FIG. 4  is a schematic sectional view of a third embodiment of the present invention; 
       FIG. 5  is a longitudinal sectional view of a turbo molecular pump main body; 
       FIG. 6  is a diagram showing an arrangement example in which a turbo molecular pump main body and a control device are integrated with each other; 
       FIG. 7  is a diagram showing another arrangement example in which a turbo molecular pump main body and a control device are integrated; 
       FIG. 8  is a schematic view of another example of a terminal structure according to the first embodiment of the present invention; and 
       FIG. 9  is a diagram showing a state in which connectors are connected with each other in the other example. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In the following, embodiments of the present invention will be described.  FIG. 1  is a schematic view of a terminal structure according to a first embodiment of the present invention. In  FIG. 1 , a male connector  500  and a female connector  600  are arranged on a turbo molecular pump main body  300  side and a control device  400  side, respectively. 
   The male connector  500  has a tubular portion in the form of a cylindrical wall  503  protruding in a cylindrical fashion toward the control device  400  side from an outer peripheral edge of a thick bottom portion  501 , and, inside the male connector  500 , there is formed a columnar cavity  504  surrounded by the cylindrical wall  503  and the bottom portion  501 . Further, a disc-like flange portion  505  is arranged around the bottom portion  501 . In the flange portion  505 , there are formed a plurality of through-holes  507 , through which bolts  509  are passed to be inserted into and fixed to an outer cylinder  127  of the turbo molecular pump main body  300 . 
   Forty-one male connector pins  511  are passed through and fixed to the bottom portion  501  while arranged at equal intervals. A head portion  511   a  at one end of each male pin  511  is formed in a semi-spherical configuration, and an elongated hole  513  is formed at another end portion  511   b  so as to allow soldering after passing a cable core (not shown). The bottom portion  501  is formed of a resin, and a sufficient sealing property is secured between it and the male pins  511 . 
   The female connector  600  arranged on the control device  400  side has a tubular portion in the form of a cylindrical wall  603  protruding in a cylindrical fashion toward the turbo molecular pump main body  300  side from an outer peripheral edge of a thick bottom portion  601 , and, in side the female connector  600 , there is formed a columnar cavity  604  surrounded by the cylindrical wall  603  and the bottom portion  601 . Further, a disc-like flange portion  605  is arranged around the bottom portion  601 . A plurality of through-holes  607  are provided in the flange portion  605 . 
   Further, a flat annular plate  609  is arranged so as to be opposed to the flange portion  605 . The flat plate  609  has through-holes  611  at positions opposed to the through-holes  607  of the flange portion  605 . Female screws are cut in the inner side of the through-holes  611 . At a center of the flat plate  609 , there is formed a circular hole  617 , through which the bottom portion  601  can pass. Elastically deformable members comprised of elastic and hollow waved washers  613  are arranged around the through-holes  607  and the through-holes  611  between the flange portion  605  and the flat plate  609 . Bolts  615  are passed through the through-holes  607 , the through-holes  611 , and the waved washers  613  to be fastened to a casing wall of the control device  400 . As shown in  FIG. 1 , small gaps are provided between the through-holes  607  and the bolts  615 . 
   Like the male pins  511  of the male connector  500 , forty-one female connector pins  621  are passed through and fixed to the bottom portion  601  while arranged at equal intervals. In a head portion  621   a  at one end of each female pin  621 , there is formed a pin insertion elongated hole  624 , into which the semi-spherical head portion  511   a  at one end of each male pin  511  is to be inserted. In another end portion  621   b  of each female pin, there is formed an elongated hole  623  so as to allow soldering after passing a cable core (not shown). A space defined by the cavity  604  and the female pins  621  is filled with a resin. 
   With this construction, the control device  400  of  FIG. 1  is moved, and the female connector  600  of the control device  400  is connected to the male connector  500  arranged in the turbo molecular pump main body  300 .  FIG. 1  shows a state prior to the connection of the connectors, and  FIG. 2  shows a state after the connection of the connectors. When the control device  400  undergoes transition from the state of  FIG. 1  to that of  FIG. 2 , the cylindrical wall  603  of the female connector  600  is fit-engaged with the cavity  504  of the male connector  500 , and, as the connection progresses, the head portions  511   a  at one ends of the male pins  511  are progressively slidably inserted into the pin insertion elongated holes  624 . 
   When, after that, the forward end of the cylindrical wall  603  of the female connector  600  abuts the bottom portion  501  of the male connector  500 , the female connector  600  on the control device  400  side, which is of low rigidity, is pushed back against the elastic force of the waved washers  613 . At this time, there has been generated a gap of approximately 1 mm between the flange portion  605  of the female connector  600  and the casing wall of the control device  400 . As a result, there is generated tension of the elastic force in the waved washers  613 , thereby making it possible to obtain an appropriate rigidity at the time of fit-engagement and to reliably maintain the connection between the pins. 
   With this construction, even when the control device  400  is inserted somewhat obliquely with respect to the turbo molecular pump main body  300 , and an excessive force is applied to the female connector  600  and the male connector  500 , the force can be mitigated through deformation of the waved washers  613 , so there is no fear of the connectors suffering damage. Thus, there is little fear of a gas leakage from the turbo molecular pump main body  300  to cause a pump heating, an electrical short-circuiting, a leakage of current, etc., thereby achieving an improvement in terms of the reliability of the pump. 
   Another example of this embodiment will be described with reference to  FIGS. 8 and 9 .  FIG. 8  is a schematic view of another terminal structure showing a state prior to the connection of the connectors, and  FIG. 9  shows a state after the connection of the connectors. 
   While in the example of  FIGS. 1 and 2  the bolts  509  are passed through the through-holes  507 , and fixed to the outer cylinder  127  of the turbo molecular pump main body  300 , in this example, a plurality of elastic members in the form of waved washers  653  are arranged between the flange portion  505  and the outer cylinder  127 , and bolts  659  are passed through the waved washers  653 . Male screws are formed in forward end portions of the bolts  659 , whereas no screws are formed in middle portions thereof as in the case of the bolts  615 . 
   Thus, when the forward end of the cylindrical wall  603  of the female connector  600  abuts the bottom portion  501  of the male connector  500 , the female connector  600  and the male connector  500  are pushed back against the elastic force of the waved washers  613  and the waved washers  653 . As a result, there is generated tension of the elastic force in the waved washers  613  and the waved washers  653 , thereby making it possible to obtain an appropriate rigidity at the time of fit-engagement and to reliably maintain the connection between the pins. 
   The outer cylinder  127  corresponds to a first member, and the casing wall of the control device  400  corresponds to a second member. The present invention is applicable not only to a turbo molecular pump, but also to a general connector connection structure. 
   Next, a second embodiment of the present invention will be described. While the conventional connector structure on the pump side has both a vacuum seal function and a conductor attachment/detachment function, in the second embodiment of the present invention, the vacuum seal function and the conductor attachment/detachment function are separated from each other.  FIG. 3  is a schematic sectional view of the second embodiment of the present invention. As shown in  FIG. 3 , an opening  701  is provided in the outer cylinder  127  of a turbo molecular pump main body  700 . A control device  800  is integrated with the turbo molecular pump main body  700  through the opening  701 . A plurality of cables  703  are passed through the opening  701 . 
   In the portions of the cables  703  situated inside the opening  701 , covering of the cables is partially peeled off to expose conductors  705 . In this state, the cables  703  are fixed in position through molding with a resin. Further, a molding member  704  thus formed of the resin is fixed to or integrated with the opening  701 . End portions of the cables  703  entering the control device  800  are connected to miniature terminals (not shown), directly connected to the board, etc. The cables  703  entering the control device  800  may be bundled for wiring, or separated into units of one to several cables to be connected to terminals. The miniature terminals may be small-sized ones as currently used in personal computers or the like, and constructed so as to be mounted to a board. 
   With this construction, the cables  703  are molded with a resin with the conductors  705  exposed, so it is possible to prevent the gas leakage through gaps between the conductors and the cable covering. As a result, it is possible to effect a vacuum seal without using a large vacuum connector. Thus, it is possible to realize a space saving and a reduction in cost. Further, the pump and the control circuit are connected to each other by the cables  703 , so even if an excessive force is applied, the cables simply deflect, and there is no fear of the connectors suffering damage. Thus, there is little fear of a gas leakage occurring from the turbo molecular pump main body  300  to cause a pump heating, an electrical short-circuiting, a leakage of current, etc., thereby achieving an improvement in terms of the reliability of the pump. 
   Next, a third embodiment of the present invention will be described. The third embodiment of the present invention is another example of the second embodiment. Also in the third embodiment of the present invention, the vacuum seal function and the conductor attachment/detachment function are separated from each other.  FIG. 4  is a schematic sectional view of the third embodiment of the present invention. As shown in  FIG. 4 , the opening  701  is provided in a wall of the outer cylinder or pump case  127  of the turbo molecular pump main body  700 . The control device  800  is integrated with the turbo molecular pump main body  700  through the opening  701 . A plurality of connector of pins  707  are passed through the opening  701 . 
   At the ends of each connector pin  707 , there are formed elongated holes  723  and  725  so as to allow soldering after passing conductors or cores  719  and  721  of cables  713  and  715 , respectively. A resin is solidification-molded with the connector pins  707  included. A covering member  729  thus formed through solidification-molding is composed of a protrusion portion  729   a  fit-engaged with the opening  701  and a bottom flange portion  729   b  covering the outer cylinder  127  of the turbo molecular pump main body  700 . A plurality of through-holes  731  are provided in the bottom flange portion  729   b  of the covering member  729 , and the covering member  729  is detachably fastened to the outer cylinder  127  of the turbo molecular pump main body  700  by bolts  733  passing through the through-holes  731 . In an edge portion of the opening  701  of the outer cylinder  127  of the turbo molecular pump main body  700 , there is provided a peripheral cutout  735 , in which a sealing ring in the form of an O-ring  737  is disposed so as to be interposed between the bottom flange portion  729   b  and the outer cylinder  127 . 
   With this construction, there is no gap between the covering member  729  and the connector pins  707 ; further, the O-ring  737  is arranged, whereby a vacuum seal is maintained. As a result, it is possible to effect a vacuum seal without using a large vacuum connector. Thus, it is possible to realize a space saving and a reduction in cost. 
   Further, soldering is effected after passing the cores  719  and  721  of the cables  713  and  715  through the elongated holes  723  and  725  at both the end portions of the pins  707 , respectively, which means the operation involved is easy to perform. The pump and the control circuit are connected to each other by the cables  713  and  715 , so even if an excessive force is applied, the cables simply deflect, and there is no fear of the connectors suffering damage. Thus, there is little fear of an electrical short-circuiting, a leakage of current, etc., thereby achieving an improvement in terms of the reliability of the pump. 
   The end portions of the cables  715  entering the control device  800  are connected to miniature terminals (not shown), directly connected to the board, etc. The cables  715  entering the control device  800  may be bundled for wiring, or separated into units of one to several cables to be connected to terminals. 
   As described above, according to the present invention, elastic retention is achieved between connectors and members retaining the connectors, so, even when an excessive force is exerted between a male connector and a female connector after one of them is inserted somewhat obliquely with respect to the other, it is possible to mitigate the force through an elastic retaining force, so there is no fear of the connectors suffering damage. Thus, there is little fear of an electrical short-circuiting, a leakage of current, etc.