Patent Publication Number: US-11035373-B2

Title: Water pump including supporting structure for impeller

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2018-0087865, filed on Jul. 27, 2018, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The following disclosure relates to a water pump including a supporting structure for an impeller, and more particularly, to a water pump including a supporting structure for an impeller having a lower manufacturing cost and reduced noise and vibration characteristics compared to a conventional water pump including a supporting structure for an impeller. 
     BACKGROUND 
     An impeller refers to a compressor that moves fluid. Such an impeller is generally used in a pump. 
       FIG. 1  illustrates a process of manufacturing a conventional water pump including an impeller. As illustrated in  FIG. 1 , the conventional water pump including an impeller includes: a shaft (not illustrated); a carbon bushing  10  coupled to the shaft; a magnetic material molding  20  housing the carbon bushing  10  therein and embedding therein, a magnetic material  21  serving as a stator for rotating the shaft; an impeller  30  rotatably coupled to the shaft at one side of the magnetic material molding  20 , discharging fluid introduced thereinto and including an upper impeller assembly  31  and a lower impeller assembly  32 ; and a pump housing (not shown) housing the carbon bushing  10 , the magnetic material molding  20  and the impeller  30 . 
     In order to serve as a rotating shaft, the shaft may rotate while being coupled to a central portion of the carbon bushing  10 ; and in order to support this shaft, a plurality of bearings are located between the carbon bushing  10  and the pump housing. When describing a position of each of the bearings in more detail with reference to  FIG. 1 , the bearing is coupled to a hole  11  of the carbon bushing  10  to support the impeller at a side of the shaft. Such a structure of the plurality of bearings has an increased manufacturing cost and excessive noise and vibration. 
     CITED REFERENCE 
     Patent Document 
     Korean Patent Laid-Open Publication No. 10-2017-0079382 (Entitled “Electric Water Pump with Waterproof Configuration,” published on Jul. 10, 2017). 
     SUMMARY 
     An embodiment of the present disclosure is directed to providing a water pump including a supporting structure for an impeller which has a lower manufacturing cost and reduced noise and vibration characteristics. 
     In one general aspect, a water pump including a supporting structure for an impeller may include: a shaft; an impeller having the shaft inserted into a center of the impeller and rotating together with the shaft to discharge an introduced fluid; a core formed on an outer circumference of the shaft; a magnetic material formed on an outer circumference of the core and forming a magnetic field rotating the shaft connected to the core and the impeller; a pump housing housing the shaft, impeller and core; and a supporting member installed between an end of the shaft and the pump housing to support the shaft. 
     The pump housing may include an upper housing and a lower housing assembled to each other, and the upper housing and the lower housing have supporting structures housing and supporting the support members and both ends of the shaft, respectively. 
     The water pump including a supporting structure for an impeller may further include a bearing provided between the supporting structure and an outer circumference of an end of the shaft. 
     The support member may have a curved or flat surface in a shaft direction. 
     When the support member has a curved surface in the shaft direction, an end of the shaft in contact with the curved surface may be flat, and when the support member has a flat surface in the shaft direction, the end of the shaft in contact with the flat surface may be curved. 
     The support member may be a spherical ball, and a partial inner portion of the supporting structure may have a curved shape corresponding to a curved surface of the ball to house the ball therein. 
     Other features and aspects will be apparent from the following detailed description, the drawings and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a flowchart illustrating a manufacturing process of a conventional water pump including an impeller. 
         FIG. 2  is a perspective view of an upper portion of a water pump including a supporting structure for an impeller according to a first exemplary embodiment in the present disclosure. 
         FIG. 3  is a perspective view of a lower portion of the water pump including a supporting structure for an impeller according to a first exemplary embodiment in the present disclosure. 
         FIG. 4  is a horizontal cross-sectional view of the water pump including a supporting structure for an impeller according to a first exemplary embodiment in the present disclosure. 
         FIG. 5  is a vertical cross-sectional view of the water pump including a supporting structure for an impeller according to a first exemplary embodiment in the present disclosure. 
         FIG. 6  is a vertical cross-sectional view of a water pump including a supporting structure for an impeller according to a second exemplary embodiment in the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Hereinafter, a water pump including a supporting structure for an impeller according to exemplary embodiments in the present disclosure are described in detail with reference to the accompanying drawings. 
     A water pump including a supporting structure for an impeller according to a first exemplary embodiment in the present disclosure may include: a shaft; an impeller; a core; a magnetic material; a pump housing; and a supporting member. 
       FIG. 2  illustrates an upper appearance of a water pump including a supporting structure for an impeller according to a first exemplary embodiment in the present disclosure; and  FIG. 3  illustrates a lower appearance of the water pump including a supporting structure for an impeller of the present disclosure. 
     An upper housing  110  and a lower housing  120  respectively illustrated in  FIGS. 2 and 3  are included in the pump housing and assembled or coupled to each other to form a housing space therein; and the housing space houses, the shaft, the impeller, the core and the magnetic material, which are other components of the water pump including a supporting structure for an impeller according to a first exemplary embodiment in the present disclosure described above. 
     As illustrated in  FIG. 2 , the upper housing  110  may be an upper portion of the pump housing and may include an inlet  111  connected to an inside of the pump housing. According to a first exemplary embodiment in the present disclosure, fluid discharged from the water pump including a supporting structure for an impeller may be introduced into the inlet  111 , and a separate flow passage may be connected to the inlet  111 . 
     The inlet  111  illustrated in  FIG. 2  may be formed in a vertical direction so that rotation of the impeller (not illustrated) inside the pump housing is not disturbed by fluid introduced into the inside of the pump housing through the inlet  111 . The fluid is introduced in the same direction as a direction of a rotation axis of the impeller, and thus fluid supplied into a central portion of the impeller does not significantly affect a rotational motion of the impeller. 
     The fluid introduced into the pump housing through the inlet  111  is discharged to an outlet  112  formed at the upper housing  110  in a horizontal direction by an impeller to be described below. The outlet  112  is connected to the inside of the pump housing, and may be formed in a direction tangential to an outer circumference of the rotating impeller. In a first exemplary embodiment in the present disclosure, it is limited that the outlet  112  is formed only in the horizontal direction, i.e. a direction tangential to the outer circumference of the rotating impeller, so that the water pump according to the embodiment has a maximal pumping efficiency. However, the present disclosure does not limit that the outlet  112  is to be formed only in the direction tangential to the outer circumference of the rotating impeller as illustrated in the embodiments in  FIGS. 2 and 3 . The outlet  112  may be formed in any direction of the pump housing as long as the fluid introduced into the pump housing by the impeller may be discharged. 
     The upper housing  110  and the lower housing  120  illustrated in  FIGS. 2 and 3  may be coupled to each other by a coupling member such as a bolt or a fitting structure. In addition, the upper housing  110  and the lower housing  120  may be made of various materials, and may be preferably made of synthetic resin for economical efficiency and easy manufacturing. 
       FIG. 4  is a horizontal cross-sectional view of an upper housing  110  of a water pump including a supporting structure for an impeller according to a first exemplary embodiment in the present disclosure. 
       FIG. 4  illustrates that an outlet passage  221  formed at an outer circumference of a rotating lower impeller  220  included in the impeller is finally connected to the outlet  112 . As illustrated in  FIGS. 2 and 3 , the fluid introduced into the inlet  111  may be introduced into a central portion as illustrated in  FIG. 4 , i.e. a shaft  300 ; moved outwardly by the rotation of the impeller including the lower impeller  220 ; and then discharged outwardly of the pump housing through the outlet passage  221  and the outlet  11 . 
     The impeller may be formed by assembling the lower impeller  220  illustrated in  FIG. 4  and the upper impeller to be described below to each other. The impeller may be coupled to the shaft  300 , and thus may rotate together with the shaft  300  as the shaft  300  rotates. 
     The impeller may have a structure from which the fluid is directly discharged, and may thus include a blade  211  directly pushing out the fluid illustrated in  FIG. 4 . 
     In the embodiment illustrated in  FIG. 4 , the blade  211  is formed in the upper impeller, but the present disclosure is not limited thereto. According to another embodiment, the blade may be formed in the lower impeller  220  and then the lower impeller  220  may be coupled to the upper impeller in which the blade is not formed. Alternatively, the blades may be respectively formed in the upper and lower impellers and then the upper and lower impellers may be coupled to each other. 
       FIG. 5  is a vertical cross-sectional view of a water pump including a supporting structure for the impeller according to a first exemplary embodiment in the present disclosure as illustrated in  FIGS. 2 and 3 . 
     As illustrated in  FIG. 5 , the shaft  300  rotates installed inside the pump housing including the upper housing  110  and the lower housing  120 ; and an upper end of the shaft  300  is housed in an upper supporting structure  113  formed inside the upper housing  110  and a lower end of the shaft  300  is housed in a lower supporting structure  123  formed inside the lower housing  120 . The shaft  300  is rotated by the motor, but the upper and lower housings  110  and  120  are not rotated. Therefore, the shaft  300  is required to be supported so that a rotational force of the shaft  300  is not transmitted to the upper and lower housings  110  and  120  and the shaft  300  is not displaced by rotation. To this end, in the present disclosure, the shaft  300  may include a first support  510  and a second support  520  as supporting members respectively positioned at the upper and lower ends of the shaft  300 ; and the first support  510  and the second support  520  may respectively support the shaft  300  at the upper and lower ends of the shaft  300 . 
     As illustrated in  FIG. 5 , the first support  510  as the supporting member may have a sectional shape in which a portion inserted into the upper supporting structure  113  is narrow, a portion facing the shaft  300  is wide, and one surface facing the shaft  300  is flat. In addition, when the one surface of the first support  510  is flat, an end of the shaft  300  in contact with the one surface of the first support  510  may protrude toward the first support  510 , while having a curvature. In this case, the shaft  300  and the first support  510  may be in point contact with each other, such that the first support  510  may support the shaft  300  with a minimized frictional force. Also, even though the one surface of the first support  510  is worn by rotation of the shaft  300 , a portion of the end of the shaft  300  may be inserted into the worn one surface of the support  510 , and thus the shaft  300  may rotate. Accordingly, a rotation axis of the shaft  300  may not be shaken. 
     The second support  520  as the supporting member has the same structure as the first support  510 ; and the second support  520  may be different from the first support  510  in being positioned at the lower end of the shaft  300  to support the shaft  300 . Therefore, a detailed description thereof is omitted. 
     Described above is a case where the first support  510  and the second support  520  are worn; however, the first support  510  and the second support  520  may be made of a material less likely to be worn by friction with the shaft  300 . 
     The first support  510  and the second support  520  may be installed in a gravity direction, i.e. a loading direction of the shaft  300 , to support the shaft  300  and the impeller  200  coupled to the shaft  300 . Accordingly, the water pump according to the present disclosure may have a more simplified structure compared to a conventional structure to support the shaft  300 , and may thus have reduced noise and vibration characteristics and a lower manufacturing cost. 
     Separate lubrication means may be used between the first and second supports  510  and  520  and the upper and lower supporting members  113  and  123 , respectively, to further reduce frictional forces between the first and second supports  510  and  520  and the upper and lower supporting members  113  and  123 , respectively. A common lubricant may be used as the lubrication means. 
     As illustrated in  FIG. 5 , a core  400  and a magnetic material  600  may be installed at a lower portion of the shaft  300 , i.e. between the shaft  300  and the lower housing  120 , to rotate the shaft  300 . 
     The core  400  serving to supply current to the rotating the rotor may be made of carbon; and a magnetic material  600  serving as a stator may be formed on an outer circumference of the core  400 . The shaft is rotated by the rotor. 
     The magnetic material  600  may include a permanent magnet to serve as the stator, and the permanent magnet may be a magnetic material such as a neodymium magnet. 
     As illustrated in  FIG. 5 , bearings  700  may be further provided at the upper and lower supporting structures  113  and  123  respectively housing the both ends of the shaft  300 , to further support the shaft  300 . The bearing  700  may be a common ball bearing, and is not limited thereto. 
       FIG. 6  is a vertical cross-sectional view of a water pump including a supporting structure for an impeller according to a second exemplary embodiment in the present disclosure. 
     As illustrated in  FIG. 6 , the water pump including a supporting structure for an impeller according to a second exemplary embodiment in the present disclosure and the water pump including a supporting structure for an impeller according to a first exemplary embodiment in the present disclosure are different from each other in that the supporting members in a first embodiment are the first support  510  and the second support  520 , whereas the supporting members in a second embodiment are a first ball  530  and a second ball  540 . 
     As illustrated in  FIG. 6 , when the supporting members are the first ball  530  and the second ball  540 , one surface of the shaft  300  may be flat, such that the first ball  530  and the second ball  540  and the one surface of the shaft  300  may be in point contact with each other, respectively. Accordingly, the both ends of the shaft  300  may be supported with minimized frictional forces, respectively. 
     As illustrated in  FIG. 6 , when the supporting members are the first ball  530  and the second ball  540  according to the present embodiment, the upper and lower supporting structures  113  and  123  may have inner surfaces of housing spaces formed corresponding to curved surfaces of the first ball  530  and the second ball  540  to house the first ball  530  and the second ball  540  therein, respectively. 
     As described above, according to the water pump including a supporting structure for an impeller in the present disclosure, the supporting members formed at the both ends of the shaft may support the shaft rotating while being coupled to the impeller. As a result, the water pump according to the present disclosure may have reduced noise and vibration characteristics caused by the rotations of the shaft and the impeller coupled to the shaft, and may have a lower manufacturing cost compared to the conventional water pump due to a more simplified structure. 
     The present disclosure is not limited to the abovementioned exemplary embodiments, but may be variously applied, and may be variously modified without departing from the gist of the present disclosure claimed in the claims.