Abstract:
A fluid pump includes a housing having a sealed interior space, at least one drive gear mounted in the interior space of the housing for driving a fluid, a magnetically inductive member coupled to the drive gear, and a stator device mounted outside the housing and located corresponding to the magnetically inductive member so that the overall thickness of the fluid pump is reduced. The stator device creates alternating energizing when supplied with electricity, thereby driving the magnetically inductive member and the drive gear to deliver the fluid.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a fluid pump, and more particularly to a fluid pump having a simplified structure for avoiding fluid leakage.  
         [0003]     2. Description of Related Art  
         [0004]      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 .  
         [0005]     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.  
         [0006]     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. Further, the driving member  40  occupies a considerable space and thus limits application of the fluid pump.  
       OBJECTS OF THE INVENTION  
       [0007]     An object of the present invention is to provide a compact fluid pump with reduced thickness for miniaturization purposes.  
         [0008]     Another object of the present invention is to provide a compact fluid pump for avoiding fluid leakage.  
         [0009]     A further object of the present invention is to provide a compact fluid pump with improved operational reliability.  
         [0010]     Still another object of the present invention is to provide a compact fluid pump having a prolonged life.  
       SUMMARY OF THE INVENTION  
       [0011]     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 magnetically inductive member coupled to the drive gear, and a stator device mounted outside the housing and located corresponding to the magnetically inductive member so that the overall thickness of the fluid pump is reduced. The stator device creates alternating energizing when supplied with electricity, thereby driving the magnetically inductive member and the drive gear to deliver the fluid.  
         [0012]     The compact 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.  
         [0013]     Preferably, the magnetically inductive member is made of magnetic material and comprises a plurality of pole sections.  
         [0014]     In an embodiment of the invention, the stator device comprises at least two coils.  
         [0015]     The stator device may further comprise at least two iron cores respectively mounted inside an associated one of the coils to increase alternating energizing intensity.  
         [0016]     The stator device may further comprise at least one sensor mounted between two coils for detecting a change in polarity during rotation of the magnetically inductive member.  
         [0017]     Preferably, the stator device is concentric with the drive gear and the magnetically inductive member.  
         [0018]     Preferably, the housing comprises a lid mounted thereto for defining the sealed interior space.  
         [0019]     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.  
         [0020]     Preferably, the lid further comprises a recessed portion for receiving the stator device.  
         [0021]     Preferably, the stator device further comprises a circuit board and the lid further comprises a recessed portion for receiving the circuit board.  
         [0022]     Preferably, the drive gear comprises a recessed portion surrounding the shaft of the drive gear for securely receiving the magnetically inductive member.  
         [0023]     Preferably, the magnetically conductive member further comprises an insulating layer to avoid rusting.  
         [0024]     Preferably, the compact fluid pump further comprises at least one driven gear rotatably mounted in the interior space of the housing and meshed with the drive gear.  
         [0025]     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  
       [0026]      FIG. 1  is a perspective view, partly exploded, of a conventional fluid pump;  
         [0027]      FIG. 2  is a perspective view, partly exploded, of a first embodiment of a compact fluid pump in accordance with the present invention;  
         [0028]      FIG. 3  is a sectional view of the compact fluid pump in  FIG. 2 ;  
         [0029]      FIG. 4  is a perspective view, partly exploded, of a second embodiment of the compact fluid pump in accordance with the present invention;  
         [0030]      FIG. 5  is a sectional view of the compact fluid pump in  FIG. 4 ;  
         [0031]      FIG. 6  is a perspective view, partly exploded, of a third embodiment of the compact fluid pump in accordance with the present invention; and  
         [0032]      FIG. 7  is a sectional view of the compact fluid pump in  FIG. 6 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]     Referring to  FIG. 2 , a first embodiment of a compact 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 stator device  50 . The compact fluid pump may drive a fluid to flow. For example, the compact 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 compact fluid pump can be used in other fluid mechanisms and operated in a similar way.  
         [0034]     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 .  
         [0035]     The lid  11  is preferably made of magnetically insulating material or non-metallic material. The lid  11  comprises a first shaft seat  111  and a second shaft seat  112 . The first shaft seat  103  of the housing  10  and the first shaft seat  111  of the lid  11  are in association with the drive gear  20  whereas the second shaft seat  104  of the housing  10  and the second shaft seat  112  of the lid  11  are in association with the driven gear  30 .  
         [0036]     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.  
         [0037]     The drive gear  20  comprises a shaft  21  that is rotatably coupled to the first shaft seat  103 , 111  of the housing  10  and the lid  11 , a recessed portion  22  in a side thereof and surrounding the shaft  21 , and a magnetically inductive member  23  fixed in the recessed portion  22  by suitable means, e.g., gluing, welding, snapping, or screwing.  
         [0038]     The magnetically inductive member  23  is made of magnetic material. The magnetically inductive member  23  may be an integrally formed circular plate. Alternatively, the magnetically inductive member  23  includes a plurality of rectangular or sectorial plates that are assembled together in a symmetric manner. In a case that the magnetically inductive member  23  is a magnet, the 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. Preferably, the 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 magnetically inductive member  23 . 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 .  
         [0039]     Still referring to  FIGS. 2 and 3 , the stator device  50  of this embodiment, preferably includes at least two coils (eight in this example) that are fixed to the lid  11  by gluing, welding, snapping, or screwing, with the coils annularly fixed on an outer side of the lid  11  along a circumference of the first shaft seat  111  of the lid  11  (or along a circumference of the first shaft seat  103  of the housing  10 ), and with the stator device  50  and the drive gear  20  being concentrically disposed. The stator device  50  can be supplied with electricity to create alternating energizing. The stator device  50  may further comprise a circuit board  51  that is fixed to the lid  11  by gluing, welding, snapping, or screwing.  
         [0040]     Still referring to  FIGS. 2 and 3 , in operation, electricity is supplied to the stator device  50  to create alternating energizing. Since the stator device  50  is concentric with the magnetically inductive member  23  of the drive gear  20 , the magnetically inductive member  23  is induced by alternating magnetic fields created by the stator device  50 , resulting in rotational movement of the drive gear  20  along a direction (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 .  
         [0041]     By using the stator device  50  outside the housing  10  to drive the drive gear  20  by indirect alternating energizing, the stator device  50  does not have to include any shaft that extends through the 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.  
         [0042]      FIGS. 4 and 5  illustrate a second embodiment of the compact fluid pump in accordance with the present invention, wherein the lid  11  further comprises a first groove  113  surrounding the first shaft seat  111  of the lid  11  and a second groove  114  surrounding the second shaft seat  112  of the lid  11 . The stator device  50  is received in the first groove  113  and the circuit board- 51  is received in the second groove  114 .  
         [0043]     Further, the drive gear  20  and the driven gear  30  may differ in size. For example, the size of the drive gear  20  may be smaller than that of the driven gear  30  and the number of the teeth of the drive gear  20  may be less than that of the driven gear  30 , and vice versa. The number of the drive gear  20  and the driven gear  30  may vary according to need.  
         [0044]     Electricity is supplied to the coils of the stator device  50  to create alternating magnetic fields. The magnetically inductive member  23  is indirectly driven to thereby drive the drive gear  20  and the driven gear  30  to turn for 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. Further, the overall thickness of the fluid pump is reduced for miniaturization purposes.  
         [0045]      FIGS. 6 and 7  illustrate a third embodiment of the compact fluid pump in accordance with the present invention, wherein the lid  11  comprises a first groove  113  for receiving the stator device  50  and a second groove  114  for receiving the circuit board  51 . Further, the stator device  50  further includes at least two iron cores (four in this example)  501  and at least one sensor  502 . Each iron core  501  is mounted inside an associated coil of the stator device  50  to increase the alternating energizing intensity. The sensor  502  is mounted between two adjacent coils of the stator device  50  and electrically connected to the circuit board  51  for detecting a change in polarity during rotation of the magnetically inductive member  23 , thereby controlling alternating energizing of the stator device  50 . 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.  
         [0046]     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.