Patent Publication Number: US-2007098576-A1

Title: Fluid pump having a simplified structure

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a fluid pump, and more particularly to a fluid pump having a simplified structure for avoiding fluid leakage.  
      2. Description of Related Art  
       FIG. 1  of the drawings illustrates a conventional fluid pump comprising a housing  10 , a drive gear  20 , a driven gear  30 , and a driving member  40 . The housing  10  receives the drive gear  20  and the driven gear  30  that mesh with each other. A lid  11  covers the housing  10 . An inlet pipe  101  is connected to a first side of the housing  10  in a location adjacent to a joining area between the drive gear  20  and the driven gear  30 . An outlet pipe  102  is connected to a second side of the housing  10  in a location opposite to the inlet pipe  101 . The driving member  40  includes a shaft  41  extending through the housing  10  and a center of the drive gear  20 . The driven gear  30  is extended through by a shaft  31  that is mounted to a seat (not shown) in the lid  11 .  
      In operation, the inlet pipe  101  and the outlet pipe  102  are coupled to a fluid-cooling type heat-dissipating module (not shown). Fluid is input via the inlet pipe  101 . The driving member  40  drives the drive gear  20  to turn (e.g., counterclockwise) through the shaft  41 , which, in turn, drives the driven gear  30  to turn (e.g., clockwise) simultaneously. The teeth of the drive gear  20  and the driven gear  30  cause the fluid to flow along an inner perimeter of the housing  10  and then be output via the outlet pipe  102 . Thus, the fluid can be fed to an object (such as a central processing chip of a computer) to be dissipated for heat-dissipating purposes.  
      However, the housing  10  must include a hole (not shown) to allow the shaft  41  of the driving member  40  to extend therethrough for engaging with the drive gear  20 , which hole results in a risk of leakage of the fluid via a gap between a circumference of the shaft  41  and a circumferential wall delimiting the hole of the housing  10 . Even though gaskets are mounted on both sides of the hole of the housing  10 , the leakage problem could not be completely solved. Further, the fluid pump, when used for dissipating heat inside a computer, operates in a high-temperature environment such that the hole of the housing  10 , the shaft  41 , and the gaskets expand and shrink in response to a change in the temperature. The housing  10 , the shaft  41 , and the gaskets are thus apt to oxidize, deform, and deteriorate. As a result, the size of the gap between the shaft  41  and the circumferential wall delimiting the hole of the housing  10  increases, aggregating the leakage problem and leading to rusting, short circuit, and damage to the fluid pump, the heat-dissipating model, and the object.  
     OBJECTS OF THE INVENTION  
      An object of the present invention is to provide a fluid pump for avoiding fluid leakage.  
      Another object of the present invention is to provide a fluid pump with improved operational reliability.  
      A further object of the present invention is to provide a fluid pump having a prolonged life.  
      Still another object of the present invention is to provide a fluid pump with improved driving efficiency with magnetic induction.  
     SUMMARY OF THE INVENTION  
      A fluid pump in accordance with the present invention comprises a housing including a sealed interior space, at least one drive gear mounted in the interior space of the housing for driving a fluid, a first magnetically inductive member coupled to the drive gear, a driving member mounted outside the housing; and a second magnetically inductive member driven by the driving member and located corresponding to the first magnetically inductive member.  
      At least one of the first magnetically inductive member and the second magnetically inductive member is made of magnetic material to provide a magnetic force for mutual attraction therebetween. When the second magnetically inductive member is driven by the driving member, the first magnetically inductive member and the drive gear are turned to drive the fluid through indirect magnetic induction provided by the second magnetically inductive member outside the housing.  
      The fluid pump may further comprise an inlet pipe and an outlet pipe connected to the housing and in communication with the interior space of the housing. The inlet pipe allows input of the fluid into the interior space of the housing and the outlet pipe allows output of the fluid out of the housing.  
      The second magnetically inductive member and the driving member are concentric with or eccentric to the first magnetically inductive member and the drive gear.  
      Preferably, the housing comprises a lid mounted thereto for defining the sealed interior space.  
      Preferably, each of the housing and the lid comprises a shaft seat. The drive gear comprises a shaft that is rotatably coupled to the shaft seat of the housing and the shaft seat of the lid.  
      Preferably, the drive gear comprises a recessed portion surrounding the shaft of the drive gear for securely receiving the first magnetically inductive member.  
      Preferably, the lid comprises a recessed portion for rotatably receiving the second magnetically inductive member.  
      Preferably, the lid comprises another recessed portion for receiving a circuit board.  
      The fluid pump may further comprise at least one driven gear rotatably mounted in the interior space of the housing and meshed with the drive gear.  
      In an embodiment of the invention, both of the first magnetically inductive member and the second magnetically inductive member are made of magnetic material.  
      Preferably, each of the first magnetically inductive member and the second magnetically inductive member comprises a plurality of north pole sections and a plurality of south pole sections. A number of the north pole sections and the south pole sections of the first magnetically inductive member is equal to, greater than, or smaller than that of the north pole sections and the south pole sections of the second magnetically inductive member.  
      In an alternative arrangement, the first magnetically inductive member is made of magnetic material and the second magnetically inductive member is made of magnetically inductive material.  
      In another alternative arrangement, the first magnetically inductive member is made of magnetically inductive material and the second magnetically inductive member is made of magnetic material.  
      Preferably, the first magnetically conductive member further comprises an insulating layer to avoid rusting.  
      Preferably, the driving member comprises a plurality of mounting members for fixing the driving member to an outside of the housing.  
      The- driving member may be an internal rotor motor or an external rotor motor.  
      The driving member may further comprise a rotor to which the second magnetically inductive member is coupled.  
      Preferably, the rotor of the driving member is a disc or an external rotor housing.  
      Other objects, advantages and novel features of this invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view, partly exploded, of a conventional fluid pump;  
       FIG. 2  is a perspective view, partly exploded, of a first embodiment of a fluid pump in accordance with the present invention;  
       FIG. 3  is a sectional view of the fluid pump in  FIG. 2 ;  
       FIG. 4  is a perspective view, partly exploded, of a second embodiment of the fluid pump in accordance with the present invention;  
       FIG. 5  is a sectional view of the fluid pump in  FIG. 4 ;  
       FIG. 6  is a perspective view, partly exploded, of a third embodiment of the fluid pump in accordance with the present invention; and  
       FIG. 7  is a sectional view of the fluid pump in  FIG. 6 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Referring to  FIG. 2 , a first embodiment of a fluid pump in accordance with the present invention comprises a housing  10 , at least one drive gear  20 , at least one driven gear  30 , and a driving member  40 . The fluid pump may drive a fluid to flow. For example, the fluid pump can be coupled with a fluid-cooling type heat-dissipating module (not shown) and drive a fluid to flow in a circulating way for dissipating an object (such as a central processing chip of a computer). The fluid pump can be used in other fluid mechanisms and operated in a similar way.  
      Referring to  FIGS. 2 and 3 , housing  10  is of an appropriate shape such as elliptic. The housing  10  includes an interior space  100 , a first shaft seat  103 , and a second shaft seat  104 . A lid  11  and a washer (or gasket)  12  are mounted to cover and seal the housing  10 . The drive gear  20  and the driven gear  30  are mounted in the interior space  100 . An inlet pipe  101  and an outlet pipe  102  are mounted to opposite sides of the housing  10  at locations adjacent to a joint area between the drive gear  20  and the driven gear  30 . Fluid enters the housing  10  via the inlet pipe  101  and exits the housing  10  via the outlet pipe  102 .  
      The lid  11  is preferably made of magnetically insulating material or non-metallic material. The lid  11  comprises a first shaft seat  111 , a second shaft seat  112 , a first groove  113 , and a second groove  114 . The first shaft seat  103  of the housing  10 , the first shaft seat  111  of the lid  11 , and the first groove  113  are in association with the drive gear  20  whereas the second shaft seat  104  of the housing  10 , the second shaft seat  112  of the lid  11 , and the second groove  114  are in association with the driven gear  30 .  
      Still referring to  FIGS. 2 and 3 , the drive gear  20  and the driven gear  30  mesh with each other and are rotatably received in the interior space  100  of the housing  10 . Each of the drive gear  20  and the driven gear  30  includes a plurality of teeth (not labeled) on a circumference thereof.  
      The drive gear  20  comprises a shaft  21 , a recessed portion  22  in a side thereof and surrounding the shaft  21 , and a first magnetically inductive member  23  fixed in the recessed portion  22  by, e.g., gluing, welding, snapping, screwing, or other suitable means.  
      The first magnetically inductive member  23  is a circular, rectangular, or sectorial plate and made of magnetic material or magnetically conductive material. In a case that the first magnetically inductive member  23  is a magnet, the first magnetically inductive member  23  includes a plurality of north pole sections N and a plurality of south pole sections S, such as eight (8) north pole sections N and eight (8) south pole sections S. The driven gear  30  includes a shaft  31  that is rotatably coupled to the second shaft seat  104  of the housing  10  and the second shaft seat  112  of the lid  11 . Preferably, the first magnetically inductive member  23  is covered by an insulating layer (not shown) to prevent from rusting resulting from long-term immersion in the fluid. The insulating layer is provided by application or injection molding to cover the first magnetically inductive member  23 .  
      Still referring to  FIGS. 2 and 3 , the driving member  40  of this embodiment is preferably a motor such as an internal rotor motor or an external rotor motor. The. driving member  40  comprises a plurality of mounting members  401 , a shaft  41 , a rotor  42 , and a second magnetically inductive element  43 . The mounting members  401  are fixed to the lid  11  by gluing, welding, snapping, or screwing, with the driving member  40  and the drive gear  20  being concentrically disposed.  
      The driving member  40  drives the shaft  41  to turn, which, in turn, turns the rotor  42 . The rotor  42  may be a disc or an external rotor housing. The second magnetically inductive member  43  is fixed on the rotor  42  by gluing, welding, snapping, or screwing. The rotor  42  and the second magnetically inductive member  43  are rotatably received in the first groove  113  of the lid  11 .  
      The second magnetically inductive member  43  is a circular, rectangular, or sectorial plate and made of magnetic material or magnetically conductive material. In a case that the second magnetically inductive member  43  is a magnet, the second magnetically inductive member  43  includes a plurality of north pole sections N and a plurality of south pole sections S, such as eight (8) north pole sections N and eight (8) south pole sections S. At lease one of the first magnetically inductive member  23  and the second magnetically inductive member  43  is magnetic to provide a power source for magnetic driving, allowing the first magnetically inductive member  23  and the second magnetically inductive member  43  to attract each other via magnetic force.  
      The driving member  40  may further comprise a circuit board (not shown) that is received in, e.g., the second groove  114  of the lid  11 . Alternatively, the second magnetically inductive member  43  can be directly coupled with the shaft  41  of the driving member  40  to omit the rotor  42 .  
      Still referring to  FIGS. 2 and 3 , in operation, the driving member  40  is empowered to drive the rotor  42  and the second magnetically inductive member  43  via the shaft  41 . Since the second magnetically inductive member  43  is concentric with the first magnetically inductive member  23  of the drive gear  20 , magnetic induction occurs to the first magnetically inductive member  23  when the second magnetically inductive member  43  turns, resulting in movements of the north pole sections N and the south pole sections S of the magnetically inductive member  43 . Hence, the first magnetically inductive member  23  and the drive gear  20  are turned (e.g., counterclockwise, see the arrow in  FIG. 2 ). Meanwhile, the drive gear  20  drives the driven gear  30  to turn clockwise (see the arrow in  FIG. 2 ). Fluid from the inlet pipe  101  is carried by the teeth on the drive gear  20  and the driven gear  30  to flow along an inner perimeter of the housing  10  and then output via the outlet pipe  102 .  
      By arrangement of the first and second magnetically inductive members  23  and  43 , the driving member  40  outside the housing  10  can drive the drive gear  20  inside the housing  10  without the need of extending the shaft  41  of the driving member  40  through the first shaft seat  111  of the lid  11 . Leakage of fluid is avoided. Thus, the sealing reliability between the housing  10  and the lid  11  is improved. The sealing effect and operational reliability of the fluid pump are improved and the life of the fluid pump is prolonged.  
       FIGS. 4 and 5  illustrate a second embodiment of the fluid pump in accordance with the present invention, wherein the second magnetically inductive member  43  of the driving member  40  is eccentric to the first magnetically inductive member  23  of the drive gear  20 . In a case that both of the first magnetically inductive member  23  and the second magnetically inductive member  43  are magnets, the number of the north pole sections N and south pole sections S of the first magnetically inductive member  23  may be different from that of the north pole sections N and south pole sections S of the second magnetically inductive member  43 . Further, the drive gear  20  and the driven gear  30  may differ in size and in the number of teeth. For example, the size of the driven gear  30  may be larger than that of the drive gear  20  and the number of the teeth of the driven gear  30  may be greater than that of the drive gear  20 , and vice versa. The number of the drive gear  20  and the driven gear  30  may vary according to need.  
      When the north pole sections N and the south pole sections S rotate, indirect magnetic induction occurs to the first magnetically inductive member  23  for driving the drive gear  20  and the driven gear  30 , thereby delivering the fluid. Similarly, the sealing effect and operational reliability of the fluid pump are improved and the life of the fluid pump is prolonged.  
       FIGS. 6 and 7  illustrate a third embodiment of the fluid pump in accordance with the present invention, wherein the second magnetically inductive member  43  of the driving member  40  is a magnet with a plurality of north pole sections N and a plurality of south pole sections S whereas the first magnetically inductive member  23  of the drive gear  20  is a magnetically conductive plate such as an iron plate. The size of the first magnetically inductive member  23  is apparently smaller than that of the second magnetically inductive member  43  and preferably equal to or smaller than that of the north pole sections N and the south pole sections S of the second magnetically inductive member  43 . The drive gear  20  is turned by the driving member  40  through use of the first and second magnetically inductive members  23  and  43 . The interior space  100  of the housing  10  is designed to receive only the drive gear  20 , as the driven gear  30  is omitted. The structure of the fluid pump is thus simplified. Rotation of the drive gear  20  is sufficient to deliver the fluid from the inlet pipe  101  side to the outlet pipe  102  side.  
      While the principles of this invention have been disclosed in connection with specific embodiments, it should be understood by those skilled in the art that these descriptions are not intended to limit the scope of the invention, and that any modification and variation without departing the spirit of the invention is intended to be covered by the scope of this invention defined only by the appended claims.