Patent Publication Number: US-8529231-B2

Title: Apparatus for cleaning rotation body and vacuum pump having the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit, under 35 U.S.C. §119, of Korean Patent Application No. 10-2009-0010346, filed on Feb. 9, 2009, the contents of which are herein incorporated by reference in their entirety. 
     BACKGROUND 
     1. Technical Field 
     Exemplary embodiments relate to an apparatus for cleaning a rotation body and a vacuum pump having the same. 
     2. Description of Related Art 
     Typically, a process chamber used in a process of manufacturing semiconductor devices or flat panel displays performs a series of processes using various kinds of chemical materials. 
     Process byproducts and residual gases generated in the process chamber are transmitted to a gas scrubber configured to separate and discharge the process byproducts and the residual gases using a gas discharger such as a vacuum pump. 
     The vacuum pump includes a stator and a rotor. The stator has an inlet port and an outlet port disposed therein. The rotor is disposed in a pump chamber in the stator. The vacuum pump may be classified as a roots type, a screw type, a claw type, etc. 
       FIG. 1  shows an exemplary vacuum pump. 
     Referring to  FIG. 1 , the vacuum pump includes a rotary shaft  11 , a pair of lobes  12 , and a first diaphragm  15 . A second diaphragm (not shown) may be disposed opposite to the first diaphragm  15 . A cylinder wall (not shown) may be disposed surrounding a pump chamber  17  between the first diaphragm  15  and the second diaphragm. The cylinder wall has an inlet port and an outlet port formed therein. The cylinder wall, the first diaphragm  15  and the second diaphragm constitute the stator. 
     The rotary shaft  11  passes through the first diaphragm  15  and the second diaphragm. The pair of opposite lobes  12  is attached to the rotary shaft  11 . The pair of lobes  12  and the rotary shaft  11  constitute the rotor  13 . That is, the rotor  13  is disposed in the pump/chamber  17 . Two rotors  13 , engaged with each other, are disposed in the pump chamber  17 . 
     The rotors  13  are rotated to suction a gas from the inlet port into the pump chamber  17 , and the suctioned gas is discharged through the outlet port. That is, the inlet port is connected to the process chamber, and the outlet port is connected to a gas scrubber. Process byproducts are suctioned from the process chamber into the pump chamber  17  through the inlet port provided in the cylinder wall, and then discharged toward the gas scrubber from the pump chamber  17  through the outlet port. 
     The process byproducts are coagulated while passing through the pump chamber to generate process byproduct lumps  19 . Some of the process byproduct lumps  19  stick to the inner surface of the pump chamber  17 . 
     Therefore, when the process byproduct lumps  19  are stuck between the lobes  12  and the first diaphragm  15  or the second diaphragm, rotation of the rotors  13  may be impeded. 
     In addition, the process byproduct lumps  19  may shorten disassembly and maintenance cycles of the vacuum pump, and cause failures of the apparatus. 
     Proposed solutions to process byproduct lumps  19  include techniques for heating the stator. Such techniques require that the vacuum pump include materials having high heat transfer efficiency, additional apparatus and increased energy to heat the stator. 
     SUMMARY 
     According to an exemplary embodiment, a rotation body cleaning apparatus includes a rotation body having one or more rotary shafts having projections, and a cleaning part disposed adjacent to the projections, having one or more rotation holes into which the one or more rotary shafts are inserted, respectively, and configured to flow a cleaning material provided into the one or more rotation holes. 
     Here, the cleaning part may include a cleaning body having a chamber formed therein, the one or more rotation holes are formed therein, a main injection hole spaced apart a predetermined distance from the rotation holes and formed at opposite surfaces of the cleaning body to be in fluid communication with the chamber, a main injection flow path connecting the main injection hole to the rotation hole, and a supply flow path connecting the chamber to a supplier configured to supply the cleaning material to the supply flow path. 
     In addition, the rotation hole may include a first rotation hole and a second rotation hole, which are spaced apart from each other, the main injection hole may be disposed at a central interface of the first rotation hole and the second rotation hole, and the main injection flow path may be bifurcated from the main injection hole to connect the first rotation hole to the second rotation hole. 
     Further, the cleaning body may have a sub injection flow path in which a sealing member surrounding the rotation hole and adhered to one surface of the projection is disposed, and sub injection holes may be further formed in the sub injection flow path. 
     A gap may be formed between the sealing member and an inner wall of the sub injection flow path adjacent to a respective one of the rotary shafts under pressure. 
     Furthermore, the sub injection flow path may further include an auxiliary injection flow path extending a predetermined distance toward the rotation hole. 
     At least one of the main injection flow path and the auxiliary injection flow path may have a width that increases towards a respective one of the rotary shafts. 
     The cleaning apparatus may further include a controller controlling the supplier to supply the cleaning material into a chamber of the cleaning part. 
     According to an exemplary embodiment, the vacuum pump includes a case having rotation guide holes formed at both ends, a rotation body having one or more rotary shafts disposed in the case to be rotatably supported by rotation guide holes formed in both ends of the case, and a plurality of projections provided at the one or more rotary shafts at predetermined intervals, and a cleaning part supported by the case and disposed in a space between the plurality of projections, having one or more rotation holes into which the one or more rotary shafts are inserted, and configured to flow a cleaning material into the one or more rotation holes. 
     Here, the cleaning part may include a cleaning body having a chamber formed therein and in which the one or more rotation holes are formed therein, a main injection hole spaced apart a predetermined distance from the rotation holes and formed at opposite surfaces of the cleaning body to be in fluid communication with the chamber, a main injection flow path connecting the main injection hole to the rotation hole, a supply flow path connecting the chamber to the exterior, and a supplier configured to supply the cleaning material to the supply flow path. 
     In addition, the rotation hole may include a first rotation hole and a second rotation hole, which are spaced apart from each other, the main injection hole may be disposed at a central interface of the first rotation hole and the second rotation hole, and the main injection flow path may be bifurcated from the main injection hole to connect the first rotation hole to the second rotation hole. 
     Further, the cleaning body may have a sub injection flow path in which a sealing member surrounding the rotation hole and adhered to one surface of the projection is disposed, and sub injection holes may be further formed in the sub injection flow path. 
     A gap may be formed between the sealing member and an inner wall of the sub injection flow path adjacent to a respective one of the rotary shafts under pressure. 
     Furthermore, the sub injection flow path may further include an auxiliary injection flow path extending a predetermined distance toward the rotation hole. 
     One of the main injection flow path and the auxiliary injection flow path may have a width that increases towards a respective one of the rotary shafts. 
     The vacuum pump may include a controller controlling the supplier to supply the cleaning material into a chamber of the cleaning part. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments are described in further detail below with reference to the accompanying drawings. It should be understood that various aspects of the drawings may have been exaggerated for clarity. 
         FIG. 1  is a perspective view of a conventional vacuum pump; 
         FIG. 2  is a perspective view of a vacuum pump having an apparatus for cleaning a rotation body in accordance with an inventive concept; 
         FIG. 3  is a cross-sectional view taken along line I-I′ of  FIG. 2 ; 
         FIG. 4  is an enlarged cross-sectional view of a reference character A of  FIG. 3 ; 
         FIG. 5  is a perspective view of an apparatus for cleaning a rotation body in accordance with an inventive concept; 
         FIG. 6  is a perspective view of another apparatus for cleaning a rotation body in accordance with an inventive concept; 
         FIG. 7  is a cross-sectional view of a sealing member disposed at an injection flow path of  FIG. 5 ; 
         FIG. 8  is a cross-sectional view showing injection of a cleaning material between sealing members from a sub injection flow path of  FIG. 7 ; 
         FIG. 9  is a view showing another example of a main injection flow path in accordance with an inventive concept; 
         FIG. 10  is a view showing another example of a sub injection flow path in accordance with an inventive concept; 
         FIG. 11  is a cross-sectional view of another example of a main injection flow path in accordance with an inventive concept; and 
         FIG. 12  is a cross-sectional view of another example of a sub injection flow path in accordance with an inventive concept. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Various exemplary embodiments will now be described more fully with reference to the accompanying drawings in which some exemplary embodiments are shown. In the drawings, the thicknesses of layers and regions may be exaggerated for clarity. Detailed illustrative embodiments are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing exemplary embodiments. Inventive concepts, however, may be embodied in many alternate forms and should not be construed as limited to only exemplary embodiments set forth herein. 
       FIG. 2  is a perspective view of a vacuum pump having an apparatus for cleaning a rotation body in accordance with an inventive concept;  FIG. 3  is a cross-sectional view taken along line I-I′ of  FIG. 2 ;  FIG. 4  is an enlarged cross-sectional view of a reference character A of  FIG. 3 ;  FIG. 5  is a perspective view of an apparatus for cleaning a rotation body in accordance with an inventive concept;  FIG. 6  is a perspective view of another apparatus for cleaning a rotation body in accordance with an inventive concept;  FIG. 7  is a cross-sectional view of a sealing member disposed at an injection flow path of  FIG. 5 ;  FIG. 8  is a cross-sectional view showing injection of a cleaning material between sealing members from a sub injection flow path of  FIG. 7 . 
     Referring to  FIGS. 2 to 8 , an apparatus for cleaning a rotation body in accordance with an inventive concept includes a rotation body  200  having one or more rotary shafts  210  having projections  220 , and one or more cleaning parts  300  disposed adjacent to at least one of the projections  220 . The cleaning part  300  having one or more rotation holes  311  into which the one or more rotary shafts  210  are inserted, and configured to flow a cleaning material provided from an exterior portion into the rotation hole  311  in a biased direction to clean the rotation body  200 . The bias may be created by, for example, an injection pressure of the cleaning material and/or movement of the rotation body  200 . 
     The cleaning part  300  includes a cleaning body  310  having a chamber  312  formed therein. The cleaning body  310  including the one or more rotation holes  311  formed therein, a main injection hole  320  spaced apart a predetermined distance from the rotation holes  311  and formed in the cleaning body  310  to be in fluid communication with the chamber  312 , a main injection flow path  321  formed in both surfaces of the cleaning body  310  to connect the main injection hole  320  to the rotation hole  311 , a supply flow path  361  configured to connect the chamber  312  to the exterior, and a supplier  360  configured to supply a cleaning material to the supply flow path  361 . Here, the cleaning body  310  has a supply hole  312   a  configured to connect the chamber  312  to the supply flow path  361 . 
     Here, the supplier  360  is electrically connected to a controller  370 . In addition, the controller  370  is electrically connected to a motor  400  coupled to the rotary shaft  210  to transmit a rotational force to the rotary shaft  210 . 
     Further, the rotation hole  311  includes a first rotation hole  311   a  and a second rotation hole  311   b , which are spaced apart from each other. Furthermore, the main injection hole  320  is disposed at a central interface of the first rotation hole  311   a  and the second rotation hole  311   b , and the main injection flow path  321  is bifurcated from the main injection hole  320  to connect the first rotation hole  311   a  to the second rotation hole  311   b.    
     Here, the main injection flow path  321  may be bifurcated from the main injection hole  320 , e.g., in a ‘V’ shape. In addition, the main injection flow path  321  may have a curved path to be connected from the main injection hole  320  to the first and second rotation holes  311   a  and  311   b.    
     Further, while not shown, the main injection flow path  321  may have a spiral inner surface. 
     Furthermore, the cleaning body  310  has a sub injection flow path  331  in which a sealing member  340  surrounding the rotation hole  311  and adhered to one surface of the projection  220  is disposed. 
     In addition, sub injection holes  330  are further formed at a plurality of positions of the sub injection flow path  331 . The sub injection holes  330  may be formed as two pairs, and may be disposed on the sub injection flow path  331  opposite each other. 
     Further, the sub injection flow path  331  may further have an auxiliary injection flow path  332  extending a predetermined distance from the rotation hole  311 . Here, the sub injection flow path  331  and the auxiliary injection flow path  332  may have spiral grooves formed at inner surfaces thereof. 
     Meanwhile, referring to  FIG. 9 , the main injection flow path  322  may have a width that increases from the main injection hole  320  toward the first and second rotation holes  311   a  and  311   b.    
     In addition, referring to  FIG. 10 , the auxiliary injection flow path  333  may also have a width that increases from the sub injection flow path  331  toward the first and second rotation holes  311   a  and  311   b.    
     Further, referring to  FIGS. 11 and 12 , a main injection hole  320 ′ and a sub injection hole  330 ′ in accordance with an inventive concept may be formed to be widened from an inner space of the chamber  312  toward an outer surface of the cleaning body  310 . 
     Hereinafter, operations of the apparatus for cleaning a rotation body as constituted above will be described. 
     Referring to  FIGS. 2 and 3 , the controller  370  operates the motor  400 , and the motor  400  transmits a rotational force to the rotary shaft  210 . The rotary shaft  210  is rotated at a certain speed. In addition, the plurality of projections  220 , such as lobes, provided at the rotary shaft  210  is also rotated. Here, the cleaning body  310  in accordance with an inventive concept is disposed between the projections  220  to clean outer surfaces of the projections  220  and the rotary shaft  210 . Further, the cleaning body  310  in accordance with an inventive concept is disposed between the projections  220  to form a fluid film to substantially prevent process byproducts such as particles from sticking to the outer surfaces of the projections  220 . 
     Operations of the cleaning part  300  will be described below with reference to  FIGS. 2 to 8 . 
     The controller  370  operates the supplier  360 , and the supplier  360  supplies a cleaning material such as a certain amount of nitrogen gas into the chamber  312  through the supply flow path  361 . 
     The cleaning material supplied into the chamber  312  is injected outside the cleaning body  310  through the main injection hole  320 . The injected cleaning material flows into the first and second rotation holes  311   a  and  311   b  along the main injection flow path  321  branched off from the main injection hole  320 . Therefore, the cleaning material may be directly supplied to an outer surface of the rotary shaft  210  rotatably inserted into the first and second rotation holes  311   a  and  311   b.    
     Here, since the cleaning material flowing along the main injection flow path  321  forms a certain injection pressure, a certain level of pressure or more may be applied to the outer surface of the rotary shaft  210  to remove foreign substances existing on the rotary shaft  210 . In addition, the cleaning material supplied as described above may form a certain thickness of fluid film at the outer surfaces of the projections  220  in addition to the outer surface of the rotary shaft  210 . 
     Further, the main injection flow path  321  formed at an opposite side of the cleaning part  300  guides the flow of the cleaning material injected through the main injection hole  320  to the first and second rotation holes  311   a  and  311   b , and therefore, the outer surface of the rotary shaft  210  and the outer surfaces of the projections  220  may be cleaned by the cleaning material having a certain thickness of fluid film at the outer surfaces. 
     Therefore, since the main injection hole  320  and the main injection flow path  321  branched off from the main injection hole  320  are formed at both surfaces of the cleaning body  310 , the rotary shaft  210  and the projections  220  exposed to both sides of the cleaning body  310  may be cleaned. 
     As a result, process byproducts (e.g., powder) may not be accumulated on the outer surfaces of the rotary shaft  210  and the projections, on which the fluid film is formed, the process byproducts may not be interposed therebetween, and contact with corrosive gases may be minimized. 
     The sub injection flow path  331 , which may be formed at both sides of the cleaning body  310 , is formed as a groove having a certain depth to surround the rotation holes  311 , and a sealing member  340  such as an O-ring having a certain diameter may be inserted into the sub injection flow path  331 . 
     The sealing member  340  is adhered between the outer surface of the cleaning body and the surfaces of the projections to substantially prevent introduction of foreign substances from the exterior along the rotary shaft  210 . 
     When the rotary shaft  210  is rotated, a certain level of pressure or more is formed in a space (hereinafter, referred to as a cleaning space) between the outer surfaces of the rotary shaft  210 , the sealing member  340  and the projections  220  to push the sealing member  340  in a direction away from the rotary shaft  210 . 
     Here, the sub injection holes  330  formed at a plurality of positions of the sub injection flow path  331  may be exposed to the cleaning space. Therefore, the cleaning material supplied into the chamber  312  may be injected into the sub injection flow path  331  through the sub injection holes  330 . 
     The cleaning material injected as described above may move along the sub injection flow path  331  and flow along the auxiliary injection flow paths  332  formed at a plurality of positions on the sub injection flow path  331  to be supplied into the cleaning space. 
     The cleaning material supplied into the cleaning space may be spread in the cleaning space, a certain thickness of fluid film may be formed at the outer surfaces of the projections and the outer surface of the rotary shaft  210  exposed to the cleaning space, and the foreign substances formed at the outer surfaces may be readily removed. 
     While it has been exemplarily described that nitrogen gas is injected into the chamber  312  through the supplier  360 , fluid other than the gas may be used as the cleaning material. 
     In addition, the controller  370  controls an operation of the supplier  360 . Here, a flow rate of the cleaning material supplied into the chamber  312  through the supplier  360  may be set by the controller  370  to be proportional to a rotational speed of the rotary shaft  210 . In this case, the motor  400  may transmit the rotational speed of the rotary shaft  210  to the controller  370  through a device such as an encoder. 
       FIG. 9  is a view showing another example of a main injection flow path in accordance with the inventive concept. Referring to  FIG. 9 , the main injection flow path  322  may have a width that increases from the main injection hole  320  toward the first and second rotation holes  311   a  and  311   b.    
       FIG. 10  is a view showing another example of a sub injection flow path in accordance with the inventive concept. Referring to  FIG. 10 , the auxiliary injection flow path  333  may also have a width that increases from the sub injection flow path  331  toward the first and second rotation holes  311   a  and  311   b.    
       FIG. 11  is a cross-sectional view of another example of a main injection flow path in accordance with the inventive concept; and  FIG. 12  is a cross-sectional view of another of a sub injection flow path in accordance with the inventive concept. Referring to  FIGS. 11 and 12 , a main injection hole  320 ′ and a sub injection hole  330 ′ may be may have a width that increases from the inner space of the chamber toward the outer surface of the cleaning body  310 . 
     Hereinafter, constitution of a vacuum pump in accordance with an exemplary embodiment of an inventive concept will be described. 
     Referring to  FIGS. 2 and 3 , the vacuum pump in accordance with an inventive concept includes a case  100  having rotation guide holes  110  formed at both ends thereof, a rotation body  200  having one or more rotary shafts  210  disposed in the case  100  and rotatably supported by the rotation guide holes  110  at both ends thereof and a plurality of projections  220  disposed at predetermined intervals on the one or more rotary shafts  210 , and a cleaning body  310  supported by the case  100  and disposed in a space between the projections  220 , having one or more rotation holes  311  into which the one or more rotary shafts  210  are inserted, and configured to flow a cleaning material supplied from the exterior into the rotation holes  311  in a biased direction to clean the rotary body  200 . The bias may be created by, for example, an injection pressure of the cleaning material and/or movement of the rotation body  200 . 
     Referring to  FIGS. 3 to 8 , the cleaning part  300  includes a cleaning body  310  having a chamber  312  formed therein and in which the one or more rotation holes  311  are formed, a main injection hole  320  spaced apart a predetermined distance from the rotation hole  311  and formed at the cleaning body  310  to be in fluid communication with the chamber  312 , a main injection flow path  321  formed at both surfaces of the cleaning body  310  and configured to connect the main injection hole  320  to the rotation hole  311 , a supply flow path  361  configured to connect the chamber  312  to the exterior, and a supplier  360  configured to supply a cleaning material into the supply flow path  361 . 
     Here, the supplier  360  is electrically connected to the controller  370 . In addition, the controller  370  is electrically connected to the motor  400  connected to the rotary shaft  210  to transmit a rotational force to the rotary shaft  210 . 
     In addition, the rotation hole  311  is constituted by a first rotation hole  311   a  and a second rotation hole  311   b , which are spaced apart from each other. Further, the main injection hole  320  is disposed at a central interface between the first rotation hole  311   a  and the second rotation hole  311   b , and the main injection flow path  321  is branched off from the main injection hole  320  to connect the first rotation hole  311   a  to the second rotation hole  311   b.    
     Here, the main injection flow path  321  may be bifurcated from the main injection hole  320 , e.g., in a ‘V’ shape. In addition, the main injection flow path  321  may form a curved path connected from the main injection hole  320  to the first and second rotation holes  311   a  and  311   b.    
     Further, the inner surface of the main injection flow path  321  may have a spiral shape. 
     Furthermore, the cleaning body  310  has a sub injection flow path  331  configured to surround the rotation hole  311  and in which a sealing member  340  adhered to one surface of the projection  220  is disposed. 
     In addition, sub injection holes  330  are further formed at a plurality of positions of the sub injection flow path  331 . The sub injection holes  330  may be provided in two pairs and disposed on the sub injection flow path  331  to oppose each other. 
     Further, the sub injection flow path  331  may further have an auxiliary injection flow path  332  extending toward the rotation hole  311  by a predetermined length. Here, the inner surface of the auxiliary injection flow path  332  may have a spiral groove. 
     Hereinafter, operation of the vacuum pump constituted as above will be described. 
     Referring to  FIGS. 2 and 3 , a controller  370  operates a motor  400 . The motor  400  transmits a rotational force to the rotary shaft  210 . The rotary shaft  210  is rotated at a certain speed. At this time, the motor  400  may transmit a rotational speed of the rotary shaft  210  to the controller  370  using a device such as an encoder. In addition, the plurality of projections  220  such as lobes provided at the rotary shaft  210  is also rotated therewith. 
     Here, the cleaning body  310  in accordance with an inventive concept is disposed between the projections  220  to clean the outer surface of the projections  220  and the outer surface of the rotary shaft  210 , and disposed between the projections  220  to form a fluid film to substantially prevent process byproducts such as particles from sticking to the outer surfaces of the projections  220 . 
     Operation of the cleaning part  300  will be described below with reference to  FIGS. 2 to 8 . 
     The controller  370  operates the supplier  360  to supply a cleaning material into the chamber  310  according to a flow rate predetermined in proportion to the rotational speed. 
     Therefore, the supplier  360  supplies a cleaning material such as a certain amount of nitrogen gas into the chamber  312  through the supply flow path  361  to correspond to a flow rate predetermined by the controller  370 . Here, the cleaning material may use a fluid other than the gas. 
     The cleaning material supplied into the chamber  312  is injected to the exterior of the cleaning body  310  through the main injection hole  320 . The injected cleaning material moves into the first rotation hole  311   a  and the second rotation hole  311   b  along the main injection flow path  321  branched off from the main injection hole  320 . Therefore, the cleaning material may be directly supplied to the exterior of the rotary shaft  210  rotatably inserted in the rotation hole  311 . 
     Since the cleaning material moving along the main injection flow path  321  forms a certain level of injection pressure, a certain level of pressure or more may be applied to the exterior of the rotary shaft  210  to remove foreign substances on the rotary shaft  210 . In addition, the cleaning material supplied as above may form a certain thickness of fluid film at the outer surface of the rotary shaft  210  and the outer surfaces of the projections  220 . 
     In addition, the main injection flow path  321  formed at the other side of the cleaning part  300  may also guide the cleaning material injected through the main injection hole  320  to be moved into the first and second rotation holes  311   a  and  311   b , and thus, the outer surface of the rotary shaft  210  and the outer surfaces of the projections  200  may be cleaned and a certain thickness of fluid film may be formed on the outer surfaces. 
     Therefore, since the main injection hole  320  and the main injection flow path  321  branched off therefrom are formed at both sides of the cleaning body  310 , the rotary shaft  210  and the projections exposed to both sides of the cleaning body  310  may be readily cleaned. 
     As a result, the process byproducts (e.g., powder) may not be accumulated on the outer surfaces of the rotary shaft  210  and the projections  220 , on which the fluid film is formed, the process byproducts may not be interposed therebetween, and contact with corrosive gases may be minimized. 
     The sub injection flow path  331  formed at both sides of the cleaning body  310  may have a certain depth of groove to surround the rotation holes  311 , and the sealing member  340  such as an O-ring having a certain diameter may be inserted into the sub injection flow path  331 . Therefore, the sealing member  340  may be adhered between the outer surface of the cleaning body  310  and the outer surfaces of the projections  220  to substantially prevent introduction of foreign substances from the exterior along the rotary shaft  210 . 
     When the rotary body  210  is rotated, a certain level of pressure or more is formed in a cleaning space between the outer surfaces of the rotary shaft  210 , the sealing member  340  and the projections  220 . 
     As shown in  FIG. 8 , the pressure formed in the cleaning space may push the sealing member  340  away from the rotary shaft  210 . Therefore, a gap d (see  FIG. 7 ) may be opening between the sealing member  340  and an inner wall of the sub injection to flow path  331  adjacent to the rotary shaft  210  to be about 0.2 mm in width. 
     Here, since the sub injection holes  330  formed at a plurality of positions of the sub injection flow path  331  may be disposed in the gap d, the sub injection holes  330  may be exposed to the cleaning space. Therefore, the cleaning material supplied into the chamber  312  may be injected into the sub injection flow path  331  through the sub injection holes  330  exposed to the gap d. 
     The cleaning material injected as above may move along the sub injection flow path  331  and flow along the auxiliary injection flow paths  332  formed at a plurality of positions on the sub injection flow path  331  to be supplied into the cleaning space. 
     The cleaning material supplied into the cleaning space may be spread in the cleaning space, a certain thickness of fluid film may be formed at the outer surfaces of the projections  220  and the outer surface of the rotary shaft  210  exposed to the cleaning space, and foreign substances formed on the outer surfaces may be readily removed. 
     Since the main injection flow path  321 , the sub injection flow path  331  and the auxiliary injection flow path  332  may have spiral inner surfaces, a flow speed of the cleaning material moved therethrough may be increased to a certain level or more. 
     In addition, as shown in  FIGS. 9 and 10 , since the main injection flow path  322  and the auxiliary injection flow path  333  may have a width that increases toward the rotary shaft  210 , a certain amount of cleaning material or more may be readily supplied around the rotary shaft  210  and into the cleaning space. 
     Further, as shown in  FIGS. 11 and 12 , since the main injection hole  320 ′ and the sub injection hole  330 ′ have diameters that increase from the chamber toward the outer surface of the cleaning body  310 , a certain flow rate of cleaning material or more supplied into the chamber  312  may be injected to the exterior of the cleaning body. 
     While not shown, the diameters of the main injection hole and the sub injection hole may be reduced from the chamber  312  toward the exterior of the cleaning body  310 . In this case, the cleaning material injected from the chamber  312  along the outer space of the cleaning body may be injected at a certain level of injection speed or more. 
     As can be seen from the foregoing, when a semiconductor manufacturing process is performed, a cleaning material can be directly supplied to an outer surface of a rotation body to substantially prevent process byproducts from sticking to a rotation body. 
     In addition, the cleaning material is supplied toward the rotary shaft at a certain position adjacent to the rotary shaft to clean the rotary shaft and outer surfaces of projections provided at the rotary shaft. 
     The foregoing is illustrative of exemplary embodiments and is not to be construed as limiting thereof. Although a few exemplary embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible in exemplary embodiments without materially departing from the novel teachings and advantages. Accordingly, all such modifications are intended to be included within the scope of inventive concepts as defined in the claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function, and not only structural equivalents but also equivalent structures. Therefore, it is to be understood that the foregoing is illustrative of various exemplary embodiments and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims.