Patent Publication Number: US-10330100-B2

Title: Pump, pump assembly and liquid cooling system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a pump, a pump assembly and a liquid cooling system and, more particularly, to a pump capable of being attached to or detached from another pump or an external device. 
     2. Description of the Prior Art 
     In general, a liquid cooling system essentially consists of a liquid cooling head, a radiator, a pump and a liquid storage box connected through a plurality of tubes. When the liquid cooling system is dissipating heat from an electronic component, the pump transports a cooling liquid to the liquid cooling head, the cooling liquid absorbs the heat generated by the electronic component, and then the radiator cools the cooling liquid. Accordingly, a flow rate outputted by the pump will influence the efficiency of the liquid cooling system as a whole. So far the flow rate outputted by one single pump has a maximum limitation. To enhance the efficiency of the liquid cooling system, the pump used currently has to be replaced by another pump with larger flow rate. Therefore, the pump of the prior art is not flexible in use and the cost of setting up the liquid cooling system may increase. 
     SUMMARY OF THE INVENTION 
     The invention provides a pump capable of being attached to or detached from another pump or an external device and further provides a pump assembly and a liquid cooling system equipped with the pump, so as to solve the aforesaid problems. 
     According to an embodiment of the invention, a pump assembly comprises a plurality of pumps, wherein each of the pumps comprises a pump body, a first opening, a second opening, a first connecting member and a second connecting member. The first opening and the second opening are located at a periphery of the pump body. The first connecting member is disposed on the first opening and the second connecting member is disposed on the second opening. The first connecting member of one of the pumps is detachably connected to the second connecting member of another of the pumps, such that each of the pumps is detachably connected to any of the pumps. 
     Preferably, one of the first connecting member and the second connecting member is a male quick connector and the other one of the first connecting member and the second connecting member is a female quick connector. 
     According to another embodiment of the invention, a pump comprises a pump body, a first opening, a second opening, a first connecting member and a second connecting member. The first opening is located at a periphery of the pump body and the second opening is located at the periphery of the pump body. The first connecting member is disposed on the first opening and the second connecting member is disposed on the second opening. 
     Preferably, one of the first connecting member and the second connecting member is a male quick connector and the other one of the first connecting member and the second connecting member is a female quick connector. 
     According to another embodiment of the invention, a liquid cooling system comprises a pump and an external device. The pump comprises a pump body, a first opening, a second opening, a first connecting member and a second connecting member. The first opening and the second opening are located at a periphery of the pump body. The first connecting member is disposed on the first opening and the second connecting member is disposed on the second opening. The external device comprises a third opening and a third connecting member. The third connecting member is disposed on the third opening. The third connecting member is detachably connected to one of the first connecting member and the second connecting member, such that the external device is detachably connected to the pump. 
     Preferably, one of the first connecting member and the second connecting member is a male quick connector, the other one of the first connecting member and the second connecting member is a female quick connector, and the third connecting member is a male quick connector or a female quick connector. 
     As mentioned in the above, since the first opening and the second opening of each pump are equipped with the first connecting member and the second connecting member, respectively, for connecting other pumps, the invention allows a user to connect a plurality of pumps in series according to the needed flow rate. Specifically, the invention may design the first connecting member and the second connecting member to be a couple of male and female quick connectors, such that the user may attach/detach the pumps to/from each other more rapidly and conveniently. Furthermore, the invention may dispose the third connecting member on the external device such as liquid cooling head, radiator, and so on and design the third connecting member to be a male quick connector or a female quick connector, such that the pump of the invention may also be attached to the external device according to practical applications, so as to form the liquid cooling system. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating a pump assembly according to an embodiment of the invention. 
         FIG. 2  is a schematic view illustrating one of the pumps shown in  FIG. 1 . 
         FIG. 3  is a schematic view illustrating a pump according to another embodiment of the invention. 
         FIG. 4  is a schematic view illustrating a pump according to another embodiment of the invention. 
         FIG. 5  is a schematic view illustrating a pump according to another embodiment of the invention. 
         FIG. 6  is a schematic view illustrating a pump assembly according to another embodiment of the invention. 
         FIG. 7  is an exploded view illustrating the pump assembly shown in  FIG. 6 . 
         FIG. 8  is an exploded view illustrating one of the pumps shown in  FIG. 7 . 
         FIG. 9  is a sectional view illustrating the pump assembly along line X-X shown in  FIG. 6 . 
         FIG. 10  is a sectional view illustrating the pump assembly along line Y-Y shown in  FIG. 6 . 
         FIG. 11  is a schematic view illustrating a pump assembly according to another embodiment of the invention. 
         FIG. 12  is an exploded view illustrating the pump assembly shown in  FIG. 11 . 
         FIG. 13  is an exploded view illustrating a pump assembly according to another embodiment of the invention. 
         FIG. 14  is a schematic view illustrating a liquid cooling system according to another embodiment of the invention. 
         FIG. 15  is an exploded view illustrating the liquid cooling system shown in  FIG. 14 . 
         FIG. 16  is a schematic view illustrating a liquid cooling system according to another embodiment of the invention. 
         FIG. 17  is an exploded view illustrating the liquid cooling system shown in  FIG. 16 . 
         FIG. 18  is a sectional view illustrating the liquid cooling system along line Z-Z shown in  FIG. 16 . 
         FIG. 19  is a schematic view illustrating a liquid cooling system according to another embodiment of the invention. 
         FIG. 20  is an exploded view illustrating the liquid cooling system shown in  FIG. 19 . 
         FIG. 21  is a sectional view illustrating the liquid cooling system along line W-W shown in  FIG. 19 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 ,  FIG. 1  is a schematic view illustrating a pump assembly  1  according to an embodiment of the invention and  FIG. 2  is a schematic view illustrating one of the pumps  10  shown in  FIG. 1 . 
     As shown in  FIGS. 1 and 2 , the pump assembly  1  comprises a plurality of pumps  10 . Each of the pumps  10  comprises a pump body  100 , a first opening  102 , a second opening  104 , a first connecting member  106  and a second connecting member  108 . The first opening  102  and the second opening  104  are located at a periphery of the pump body  100 . In this embodiment, the first opening  102  may be an outlet and the second opening  104  may be an inlet, or alternatively, the first opening  102  may be an inlet and the second opening  104  may be an outlet. The first connecting member  106  is disposed on the first opening  102  and the second connecting member  108  is disposed on the second opening  104 . Accordingly, the first connecting member  106  of one of the pumps  10  may be detachably connected to the second connecting member  108  of another of the pumps  10 , such that each of the pumps  10  may be detachably connected to any of the pumps  10 , as shown in  FIG. 1 . 
     In other words, since the first opening  102  and the second opening  104  of each pump  10  are equipped with the first connecting member  106  and the second connecting member  108 , respectively, for connecting other pumps  10 , the invention allows a user to connect a plurality of pumps  10  in series according to the needed flow rate. The pump assembly  1  shown in  FIG. 1  consists of three pumps  10  connected to each other in series by the first connecting member  106  and the second connecting member  108  correspondingly. However, the user may connect two or more than three pumps  10  in series according to the needed flow rate. 
     The pump assembly  1  of the invention may be applied to, but not limited to, a liquid cooling system. It should be noted that the interior structure and the principle of the pump body  100  of the pump  10  is well known by one skilled in the art, so those will not be depicted herein again. Furthermore, the number and the position of the first opening  102  and the second opening  104  of each pump  10  may be determined according to practical applications, so those are not limited by the embodiment shown in the figure. For example, the pump  10  may also have two or more than two first openings  102  and/or second openings  104  according to practical applications. When the pump  10  has two or more than two first openings  102  and/or second openings  104 , each first opening  102  may be equipped with a first connecting member  106  and each second opening  104  may be equipped with a second connecting member  108 . In this embodiment, the first opening  102  and the second opening  104  are located at two adjacent surfaces of the pump body  100 , respectively. However, in another embodiment, the first opening  102  and the second opening  104  may also be located at opposite surfaces of the pump body  100 , respectively. 
     In this embodiment, one of the first connecting member  106  and the second connecting member  108  may be a male quick connector and the other one of the first connecting member  106  and the second connecting member  108  may be a female quick connector. In other words, the invention may design the first connecting member  106  and the second connecting member  108  to be a couple of male and female quick connectors, such that the user may attach/detach the pumps  10  to/from each other more rapidly and conveniently. In some embodiments, the quick connectors served as the first connecting member  106  and the second connecting member  108  may have quick attaching/detaching structure and have some structures for preventing a working fluid (e.g. cooling liquid) from leaking out of the pumps  10  while the pumps  10  are being attached to or detached from each other. In other embodiments, the first connecting member  106  and the second connecting member  108  may also be connected to each other in a screw manner. 
     In this embodiment, the pump body  100  of each of the pumps  10  is regular polygonal (e.g. square, regular pentagon, regular hexagon, etc.). Accordingly, the user may connect the pumps  10  in series by the first connecting member  106  and the second connecting member  108  correspondingly to form a regular or special shape, like building blocks or jigsaw puzzle. However, in another embodiment, the pump body  100  of each of the pumps  10  may also be arbitrary polygonal, circular or other shapes and it is not limited to regular polygonal. Moreover, the shape of the pump body  100  of each of the pumps  10  may be the same of different according to practical applications. 
     Referring to  FIG. 3 ,  FIG. 3  is a schematic view illustrating a pump  20  according to another embodiment of the invention. The difference between the pump  20  and the aforesaid pump  10  is that the pump  20  further comprises a first electrical pad  200  and a second electrical pad  202 , as shown in  FIG. 3 . In this embodiment, the first electrical pad  200  is disposed on the first connecting member  106  and the second electrical pad  202  is corresponding to the first electrical pad  200  and disposed on the second connecting member  108 . However, in another embodiment, the first electrical pad  200  may also be disposed around the first opening  102  and the second electrical pad  202  corresponding to the first electrical pad  200  may also be disposed around the second opening  104 . In other words, the first electrical pad  200  may be selectively disposed on the first connecting member  106  or around the first opening  102  and the second electrical pad  202  corresponding to the first electrical pad  200  may be selectively disposed on the second connecting member  108  or around the second opening  104 . The invention is not limited to the embodiment shown in  FIG. 3 . When the first connecting member  106  of one of the pumps  20  is connected to the second connecting member  108  of another of the pumps  20 , the first electrical pad  200  and the second electrical pad  202  of the two pumps  20  are electrically connected to each other. Therefore, as long as one of the pumps  20  connected in series is supplied with power, other pumps  20  may obtain power through the first electrical pad  200  and the second electrical pad  202 . Accordingly, the invention may further save circuit layout space for the pump  20 . It should be noted that the same elements in  FIG. 3  and  FIG. 2  are represented by the same numerals, so the repeated explanation will not be depicted herein again. 
     Referring to  FIG. 4 ,  FIG. 4  is a schematic view illustrating a pump  30  according to another embodiment of the invention. The difference between the pump  30  and the aforesaid pump  10  is that the pump  30  further comprises a sensor  300 , as shown in  FIG. 4 . The sensor  300  is used for sensing a flow rate, a pressure and/or a temperature of a working fluid (not shown) in the pump  30 . In other words, the sensor  300  may be a flow rate sensor, a pressure sensor, a temperature sensor or a multi-function sensor capable of sensing at least two of flow rate, pressure and temperature simultaneously. Needless to say, the invention may also dispose the flow rate sensor, the pressure sensor and the temperature sensor in the pump  30  to sense the flow rate, the pressure and the temperature, respectively. In practical applications, the sensor  300  may be disposed around the first opening  102 , around the second opening  104  or at other suitable positions in the pump body  100 . It should be noted that the same elements in  FIG. 4  and  FIG. 2  are represented by the same numerals, so the repeated explanation will not be depicted herein again. 
     Referring to  FIG. 5 ,  FIG. 5  is a schematic view illustrating a pump  40  according to another embodiment of the invention. The difference between the pump  40  and the aforesaid pump  10  is that the pump  40  further comprises a light emitting unit  400 , as shown in  FIG. 5 . In this embodiment, the light emitting unit  400  may be disposed at a suitable position of the periphery of the pump body  100 . The user may notice the position of the pump  40  rapidly according to the light emitted by the light emitting unit  400 . Furthermore, the invention may also utilize the light emitting unit  400  to emit light with specific color(s), so as to enhance visual effect. In practical applications, the light emitting unit  400  may be a light emitting diode, a light bar or other light sources. It should be noted that the same elements in  FIG. 5  and  FIG. 2  are represented by the same numerals, so the repeated explanation will not be depicted herein again. 
     Referring to  FIGS. 6 and 10 ,  FIG. 6  is a schematic view illustrating a pump assembly  5  according to another embodiment of the invention,  FIG. 7  is an exploded view illustrating the pump assembly  5  shown in  FIG. 6 ,  FIG. 8  is an exploded view illustrating one of the pumps  50  shown in  FIG. 7 ,  FIG. 9  is a sectional view illustrating the pump assembly  5  along line X-X shown in  FIG. 6 , and  FIG. 10  is a sectional view illustrating the pump assembly  5  along line Y-Y shown in  FIG. 6 . 
     As shown in  FIGS. 6 to 10 , the pump assembly  5  comprises a plurality of pumps  50 . Each of the pumps  50  comprises a pump body  500 , a first opening  502 , a second opening  504 , a first connecting member  506  and a second connecting member  508 . The first opening  502  and the second opening  504  are located at a periphery of the pump body  500 . In this embodiment, the first opening  502  may be an outlet and the second opening  504  may be an inlet, or alternatively, the first opening  502  may be an inlet and the second opening  504  may be an outlet. The first connecting member  506  is disposed on the first opening  502  and the second connecting member  508  is disposed on the second opening  504 . Accordingly, the first connecting member  506  of one of the pumps  50  may be detachably connected to the second connecting member  508  of another of the pumps  50 , such that each of the pumps  50  may be detachably connected to any of the pumps  50 , as shown in  FIGS. 6, 9 and 10 . 
     In other words, since the first opening  502  and the second opening  504  of each pump  50  are equipped with the first connecting member  506  and the second connecting member  508 , respectively, for connecting other pumps  50 , the invention allows a user to connect a plurality of pumps  50  in series according to the needed flow rate. The pump assembly  5  shown in  FIG. 6  consists of two pumps  50  connected to each other in series by the first connecting member  506  and the second connecting member  508  correspondingly. However, the user may connect more than two pumps  50  in series according to the needed flow rate. 
     The pump assembly  5  of the invention may be applied to, but not limited to, a liquid cooling system. It should be noted that the interior structure and the principle of the pump body  500  of the pump  50  is well known by one skilled in the art, so those will not be depicted herein again. Furthermore, the number and the position of the first opening  502  and the second opening  504  of each pump  50  may be determined according to practical applications, so those are not limited by the embodiment shown in the figure. For example, the pump  50  may also have two or more than two first openings  502  and/or second openings  504  according to practical applications. When the pump  50  has two or more than two first openings  502  and/or second openings  504 , each first opening  502  may be equipped with a first connecting member  506  and each second opening  504  may be equipped with a second connecting member  508 . In this embodiment, the first opening  502  and the second opening  504  are located at two adjacent surfaces of the pump body  500 , respectively. However, in another embodiment, the first opening  502  and the second opening  504  may also be located at opposite surfaces of the pump body  500 , respectively. 
     In this embodiment, one of the first connecting member  506  and the second connecting member  508  may be a male quick connector and the other one of the first connecting member  506  and the second connecting member  508  may be a female quick connector. In other words, the invention may design the first connecting member  506  and the second connecting member  508  to be a couple of male and female quick connectors, such that the user may attach/detach the pumps  50  to/from each other more rapidly and conveniently. As shown in  FIGS. 6 to 10 , the first connecting member  506  is a female quick connector and the second connecting member  508  is a male quick connector. In some embodiments, the quick connectors served as the first connecting member  506  and the second connecting member  508  may have quick attaching/detaching structure and have some structures for preventing a working fluid (e.g. cooling liquid) from leaking out of the pumps  50  while the pumps  50  are being attached to or detached from each other. In other embodiments, the first connecting member  506  and the second connecting member  508  may also be connected to each other in a screw manner. 
     In this embodiment, the pump body  500  of each of the pumps  50  is regular polygonal (e.g. square, regular pentagon, regular hexagon, etc.). Accordingly, the user may connect the pumps  50  in series by the first connecting member  506  and the second connecting member  508  correspondingly to form a regular or special shape, like building blocks or jigsaw puzzle. However, in another embodiment, the pump body  500  of each of the pumps  50  may also be arbitrary polygonal, circular or other shapes and it is not limited to regular polygonal. Moreover, the shape of the pump body  500  of each of the pumps  50  may be the same of different according to practical applications. 
     In this embodiment, each of the pumps  50  may further comprise a first electrical pad  510  and a second electrical pad  512 . As shown in  FIG. 7 , the first electrical pad  510  may be disposed around the first opening  502  and the second electrical pad  512  corresponding to the first electrical pad  510  may be disposed around the second opening  504 . Furthermore, each of the pumps  50  may further comprise a circuit board  514  and a power connector  516 . As shown in  FIG. 9 , the circuit board  514  and the power connector  516  are disposed in the pump body  500 , wherein the power connector  516 , the first electrical pad  510  and the second electrical pad  512  are electrically connected to the circuit board  514 . 
     When the first connecting member  506  of one of the pumps  50  is connected to the second connecting member  508  of another of the pumps  50 , the first electrical pad  510  is electrically connected to the second electrical pad  512  correspondingly. The user may connect a power cable with a power source (not shown) to the power connector  516 , such that power can be supplied to the first electrical pad  510  and the second electrical pad  512  through the power connector  516 . Therefore, as long as one of the pumps  50  connected in series is supplied with power, other pumps  50  may obtain power through the first electrical pad  510  and the second electrical pad  512 . Accordingly, the invention may further save circuit layout space for the pump  50 . 
     In this embodiment, each of the pumps  50  may further comprise a guiding pin  518  and a guiding hole  520 . As shown in  FIG. 7 , each of the pumps  50  comprises two guiding pins  518  and two guiding holes  520 . The guiding pins  518  are disposed on the pump body  500  and around the first connecting member  506 . The guiding holes  520  are formed on the pump body  500  and around the second connecting member  508 . When a user wants to connect two pumps  50  in series, the user may insert the guiding pins  518  into the guiding holes  520 , so as to connect the first connecting member  506  of one pump  50  and the second connecting member  508  of another pump  50 . As shown in  FIG. 10 , when the first connecting member  506  of one pump  50  is connected to the second connecting member  508  of another pump  50 , the guiding pins  518  are inserted into the guiding holes  520  correspondingly. In other words, the guiding pins  518  and the guiding holes  520  can assist the user in connecting two pumps  50  in series rapidly and conveniently. 
     In this embodiment, each of the pumps  50  may further comprise a release button  522  and a first resilient member  524 . As shown in  FIG. 8 , each of the pumps  50  comprises two release buttons  522  and two first resilient members  524 . The first resilient members  524  may be, but not limited to, springs. As shown in  FIG. 10 , the release button  522  is movably disposed on the pump body  500  and the first resilient member  524  is located between and abuts against the release button  522  and the pump body  500 . The release button  522  has an engaging portion  5220 . A through hole  526  is formed on the pump body  500  and communicates with the guiding hole  520 . The engaging portion  5220  of the release button  522  is inserted into the through hole  526  and passes through the guiding hole  520 . The guiding pin  518  has an engaging groove  5180 . 
     As shown in  FIG. 10 , when the guiding pin  518  is inserted into the guiding hole  520 , the engaging portion  5220  of the release button  522  is engaged with the engaging groove  5180  of the guiding pin  518 . Accordingly, when two pumps  50  are connected to each other through the first connecting member  506  and the second connecting member  508 , the two pumps  50  will not come off each other due to the engagement formed by the engaging portion  5220  of the release button  522  and the engaging groove  5180  of the guiding pin  518 . If the user wants to detach the two pumps  50  from each other, the user may press the release button  522  in the direction indicated by an arrow A, so as to disengage the engaging portion  5220  from the engaging groove  5180  of the guiding pin  518 . Once the engaging portion  5220  of the release button  522  is disengaged from the engaging groove  5180  of the guiding pin  518 , the user can detach the two pumps  50  from each other by separating the first connecting member  506  and the second connecting member  508  from each other. It should be noted that when the user presses the release button  522 , the first resilient member  524  is compressed by the release button  522 . When the user looses the release button  522 , the first resilient member  524  generates an elastic force to push the release button  522  back. 
     In this embodiment, each of the pumps  50  may further comprise a second resilient member  528  disposed in the guiding hole  520 . As shown in  FIG. 8 , each of the pumps  50  comprises two second resilient members  528 . The second resilient members  528  may be, but not limited to, springs. As shown in  FIG. 10 , when the guiding pin  518  is inserted into the guiding hole  520 , the second resilient member  528  is compressed by the guiding pin  518 . When the release button  522  is pressed to disengage the engaging portion  5220  from the engaging groove  5180  of the guiding pin  518 , the second resilient member  528  generates an elastic force to push the guiding pin  518  out of the guiding hole  520 . Accordingly, the user can detach the pumps  50  from each other much more easily. 
     In this embodiment, each of the pumps  50  may further comprise a washer  530  selectively disposed on one of the first connecting member  506  and the second connecting member  508 . As shown in  FIG. 7 , the washer  530  is disposed on the second connecting member  508 . However, in another embodiment, the washer  530  may be disposed on the first connecting member  506 . As shown in  FIGS. 9 and 10 , when the first connecting member  506  is connected to the second connecting member  508 , the washer  530  is located between and abuts against the first connecting member  506  and the second connecting member  508 , so as to prevent a working fluid (e.g. cooling liquid) from leaking out of the pumps  50 . 
     Referring to  FIGS. 11 and 12 ,  FIG. 11  is a schematic view illustrating a pump assembly  6  according to another embodiment of the invention and  FIG. 12  is an exploded view illustrating the pump assembly  6  shown in  FIG. 11 . The difference between the pump assembly  6  and the aforesaid pump assembly  5  is that each of the pumps  60  of the pump assembly  6  comprises a rotating member  600 . As shown in  FIGS. 11 and 12 , each of the pumps  60  comprises two rotating members  600 . The rotating member  600  is rotatably disposed on the pump body  500  and the rotating member  600  has an engaging portion  602 . Furthermore, a recess  604  is formed on the pump body  500  and the recess  604  has an engaging groove  606 . In this embodiment, when the first connecting member  506  is connected to the second connecting member  508 , a part of the rotating member  600  is accommodated in the recess  604  correspondingly. When the part of the rotating member  600  is accommodated in the recess  604 , the rotating member  600  is capable of being rotated to enable the engaging portion  602  to be engaged with or disengaged from the engaging groove  606 . 
     For example, when the first connecting member  506  is connected to the second connecting member  508  and the part of the rotating member  600  is accommodated in the recess  604 , the user may rotate the rotating member  600  to enable the engaging portion  602  to be engaged with the engaging groove  606 . Accordingly, two pumps  60  are connected to each other through the first connecting member  506  and the second connecting member  508  and will not come off each other due to the engagement formed by the engaging portion  602  of the rotating member  600  and the engaging groove  606  of the recess  604 . If the user wants to detach the two pumps  60  from each other, the user may rotate the rotating member  600  to enable the engaging portion  602  to be disengaged from the engaging groove  606 . Once the engaging portion  602  of the rotating member  600  is disengaged from the engaging groove  606  of the recess  604 , the user can detach the two pumps  60  from each other by separating the first connecting member  506  and the second connecting member  508  from each other. In other words, the invention may replace the aforesaid guiding pin  518  and guiding hole  520  by the rotating member  600  and the recess  604 , so as to achieve the same function. It should be noted that the same elements in  FIGS. 11-12  and  FIGS. 6-10  are represented by the same numerals, so the repeated explanation will not be depicted herein again. 
     Referring to  FIG. 13 ,  FIG. 13  is an exploded view illustrating a pump assembly  6 ′ according to another embodiment of the invention. The difference between the pump assembly  6 ′ and the aforesaid pump assembly  6  is that each of the pumps  60  of the pump assembly  6 ′ further comprises a first electrical pad  610  and a second electrical pad  612 . In this embodiment, the first electrical pad  610  and the second electrical pad  612  are circular. As shown in  FIG. 13 , the first electrical pad  610  is disposed around the first opening  502  and the second electrical pad  612  is corresponding to the first electrical pad  610  and disposed around the second opening  504 . When the first connecting member  506  of one of the pumps  60  is connected to the second connecting member  508  of another of the pumps  60 , the first electrical pad  610  and the second electrical pad  612  of the two pumps  60  are electrically connected to each other. Therefore, as long as one of the pumps  60  connected in series is supplied with power, other pumps  60  may obtain power through the first electrical pad  610  and the second electrical pad  612 . Accordingly, the invention may further save circuit layout space for the pump  60 . It should be noted that the same elements in  FIG. 13  and  FIGS. 11-12  are represented by the same numerals, so the repeated explanation will not be depicted herein again. 
     It should be noted that the first electrical pad  610  and the second electrical pad  612  may consist of at least one signal line and at least one power line, wherein the signal line is used for detecting whether the first electrical pad  610  and the second electrical pad  612  are electrically connected to each other well and the power line is used for supplying power between the first electrical pad  610  and the second electrical pad  612 . Since the first electrical pad  610  and the second electrical pad  612  are circular, the two pumps  60  connected to each other can rotate with respect to each other and the first electrical pad  610  and the second electrical pad  612  can still keep good electrical connection. 
     Referring to  FIGS. 14 and 15 ,  FIG. 14  is a schematic view illustrating a liquid cooling system  7  according to another embodiment of the invention and  FIG. 15  is an exploded view illustrating the liquid cooling system  7  shown in  FIG. 14 . As shown in  FIGS. 14 and 15 , the liquid cooling system  7  comprises a pump  50  and an external device  70 . It should be noted that the structure of the pump  50  has been mentioned in the above, so it will not be depicted herein again. The external device  70  comprises a third opening  700  and a third connecting member  702 . As shown in  FIG. 15 , the third connecting member  702  is disposed on the third opening  700 . Accordingly, the third connecting member  702  of the external device may be detachably connected to the second connecting member  508  of the pump  50 , such that the external device  70  may be detachably connected to the pump  50 , as shown in  FIG. 14 . 
     In this embodiment, the second opening  504  may be an outlet and the third opening  700  may be an inlet, or alternatively, the second opening  504  may be an inlet and the third opening  700  may be an outlet. Furthermore, the external device  70  may be, but not limited to, a radiator. Moreover, the third connecting member  702  may be a male quick connector or a female quick connector according to the type of the second connecting member  508 . For example, as shown in  FIG. 15 , since the second connecting member  508  of the pump  50  is a male quick connector, the third connecting member  702  should be a female quick connector correspondingly. 
     Referring to  FIGS. 16 to 18 ,  FIG. 16  is a schematic view illustrating a liquid cooling system  8  according to another embodiment of the invention,  FIG. 17  is an exploded view illustrating the liquid cooling system  8  shown in  FIG. 16 , and  FIG. 18  is a sectional view illustrating the liquid cooling system  8  along line Z-Z shown in  FIG. 16 . As shown in  FIGS. 16 to 18 , the liquid cooling system  8  comprises a pump  50  and an external device  80 . It should be noted that the structure of the pump  50  has been mentioned in the above, so it will not be depicted herein again. The external device  80  comprises a third opening  800  and a third connecting member  802 . As shown in  FIG. 17 , the third connecting member  802  is disposed on the third opening  800 . Accordingly, the third connecting member  802  of the external device  80  may be detachably connected to the first connecting member  506  of the pump  50 , such that the external device  80  may be detachably connected to the pump  50 , as shown in  FIG. 16 . 
     In this embodiment, the first opening  502  may be an outlet and the third opening  800  may be an inlet, or alternatively, the first opening  502  may be an inlet and the third opening  800  may be an outlet. Furthermore, the external device  80  may be, but not limited to, a liquid cooling head. Moreover, the third connecting member  802  may be a male quick connector or a female quick connector according to the type of the first connecting member  506 . For example, as shown in  FIG. 17 , since the first connecting member  506  of the pump  50  is a female quick connector, the third connecting member  802  should be a male quick connector correspondingly. 
     In this embodiment, the external device  80  may further comprise a guiding hole  820 . As shown in  FIG. 17 , the external device  80  comprises two guiding holes  820 . The guiding holes  820  are formed around the third connecting member  802 . When a user wants to connect the pump  50  and the external device  80 , the user may insert the guiding pins  518  of the pump  50  into the guiding holes  820  of the external device  80 , so as to connect the first connecting member  506  of the pump  50  and the third connecting member  802  of the external device  80 . As shown in  FIG. 18 , when the first connecting member  506  of the pump  50  is connected to the third connecting member  802  of the external device  80 , the guiding pins  518  are inserted into the guiding holes  820  correspondingly. In other words, the guiding pins  518  and the guiding holes  820  can assist the user in connecting the pump  50  and the external device  80  rapidly and conveniently. 
     In this embodiment, the external device  80  may further comprise a release button  822  and a first resilient member  824 . As shown in  FIG. 18 , the external device  80  comprises two release buttons  822  and two first resilient members  824 . The first resilient members  824  may be, but not limited to, springs. The release button  822  is movably disposed on the external device  80  and the first resilient member  824  is located between and abuts against the release button  822  and the external device  80 . The release button  822  has an engaging portion  8220 . A through hole  826  is formed on the external device  80  and communicates with the guiding hole  820 . The engaging portion  8220  of the release button  822  is inserted into the through hole  826  and passes through the guiding hole  820 . 
     As shown in  FIG. 18 , when the guiding pin  518  of the pump  50  is inserted into the guiding hole  820  of the external device  80 , the engaging portion  8220  of the release button  822  is engaged with the engaging groove  5180  of the guiding pin  518 . Accordingly, when the pump  50  and the external device  80  are connected to each other through the first connecting member  506  and the third connecting member  802 , the pump  50  and the external device  80  will not come off each other due to the engagement formed by the engaging portion  8220  of the release button  822  and the engaging groove  5180  of the guiding pin  518 . If the user wants to detach the pump  50  and the external device  80  from each other, the user may press the release button  822  in the direction indicated by an arrow A, so as to disengage the engaging portion  8220  from the engaging groove  5180  of the guiding pin  518 . Once the engaging portion  8220  of the release button  822  is disengaged from the engaging groove  5180  of the guiding pin  518 , the user can detach the pump  50  and the external device  80  from each other by separating the first connecting member  506  and the third connecting member  802  from each other. It should be noted that when the user presses the release button  822 , the first resilient member  824  is compressed by the release button  822 . When the user looses the release button  822 , the first resilient member  824  generates an elastic force to push the release button  822  back. 
     In this embodiment, the external device  80  may further comprise a second resilient member  828  disposed in the guiding hole  820 . As shown in  FIG. 18 , the external device  80  comprises two second resilient members  828 . The second resilient members  828  may be, but not limited to, springs. When the guiding pin  518  of the pump  50  is inserted into the guiding hole  820  of the external device  80 , the second resilient member  828  is compressed by the guiding pin  518 . When the release button  822  is pressed to disengage the engaging portion  8220  from the engaging groove  5180  of the guiding pin  518 , the second resilient member  828  generates an elastic force to push the guiding pin  518  out of the guiding hole  820 . Accordingly, the user can detach the pump  50  and the external device  80  from each other much more easily. 
     In this embodiment, the external device  80  may further comprise a washer  830  disposed on the third connecting member  802 . As shown in  FIG. 18 , when the first connecting member  506  is connected to the third connecting member  802 , the washer  830  abuts against between the first connecting member  506  and the third connecting member  802 , so as to prevent a working fluid (e.g. cooling liquid) from leaking out of the pump  50  and the external device  80 . 
     Referring to  FIGS. 19 to 21 ,  FIG. 19  is a schematic view illustrating a liquid cooling system  9  according to another embodiment of the invention,  FIG. 20  is an exploded view illustrating the liquid cooling system  9  shown in  FIG. 19 , and  FIG. 21  is a sectional view illustrating the liquid cooling system  9  along line W-W shown in  FIG. 19 . As shown in  FIGS. 19 to 21 , the liquid cooling system  9  comprises a pump  50  and an external device  90 . It should be noted that the structure of the pump  50  has been mentioned in the above, so it will not be depicted herein again. The external device  90  comprises a third opening  900  and a third connecting member  902 . As shown in  FIG. 20 , the third connecting member  902  is disposed on the third opening  900 . Accordingly, the third connecting member  902  of the external device  90  may be detachably connected to the second connecting member  508  of the pump  50 , such that the external device  90  may be detachably connected to the pump  50 , as shown in  FIG. 19 . 
     In this embodiment, the second opening  504  may be an outlet and the third opening  900  may be an inlet, or alternatively, the second opening  504  may be an inlet and the third opening  900  may be an outlet. Furthermore, the external device  90  may be, but not limited to, a tank for containing a cooling liquid (e.g. water, oil, and so on). Moreover, the third connecting member  902  may be a male quick connector or a female quick connector according to the type of the second connecting member  508 . For example, as shown in  FIG. 20 , since the second connecting member  508  of the pump  50  is a male quick connector, the third connecting member  902  should be a female quick connector correspondingly. 
     In this embodiment, the external device  90  may further comprise a guiding pin  918 . As shown in  FIG. 20 , the external device  90  comprises two guiding pins  918 . The guiding pins  918  are disposed around the third connecting member  902 . When a user wants to connect the pump  50  and the external device  90 , the user may insert the guiding pins  918  of the external device  90  into the guiding holes  520  of the pump  50 , so as to connect the second connecting member  508  of the pump  50  and the third connecting member  902  of the external device  90 . As shown in  FIG. 21 , when the second connecting member  508  of the pump  50  is connected to the third connecting member  902  of the external device  90 , the guiding pins  918  are inserted into the guiding holes  520  correspondingly. In other words, the guiding pins  918  and the guiding holes  520  can assist the user in connecting the pump  50  and the external device  90  rapidly and conveniently. 
     In this embodiment, the guiding pin  918  has an engaging groove  9180 . As shown in  FIG. 21 , when the guiding pin  918  of the external device  90  is inserted into the guiding hole  520  of the pump  50 , the engaging portion  5220  of the release button  522  is engaged with the engaging groove  9180  of the guiding pin  918 . Accordingly, when the pump  50  and the external device  90  are connected to each other through the second connecting member  508  and the third connecting member  902 , the pump  50  and the external device  90  will not come off each other due to the engagement formed by the engaging portion  5220  of the release button  522  and the engaging groove  9180  of the guiding pin  918 . If the user wants to detach the pump  50  and the external device  90  from each other, the user may press the release button  522  in the direction indicated by an arrow A, so as to disengage the engaging portion  5220  from the engaging groove  9180  of the guiding pin  918 . Once the engaging portion  5220  of the release button  522  is disengaged from the engaging groove  9180  of the guiding pin  918 , the user can detach the pump  50  and the external device  90  from each other by separating the second connecting member  508  and the third connecting member  902  from each other. It should be noted that when the user presses the release button  522 , the first resilient member  524  is compressed by the release button  522 . When the user looses the release button  522 , the first resilient member  524  generates an elastic force to push the release button  522  back. 
     Furthermore, when the guiding pin  918  of the external device  90  is inserted into the guiding hole  520  of the pump  50 , the second resilient member  528  is compressed by the guiding pin  918 . When the release button  522  is pressed to disengage the engaging portion  5220  from the engaging groove  9180  of the guiding pin  918 , the second resilient member  528  generates an elastic force to push the guiding pin  918  out of the guiding hole  520 . Accordingly, the user can detach the pump  50  and the external device  90  from each other much more easily. 
     As shown in  FIG. 21 , when the second connecting member  508  is connected to the third connecting member  902 , the washer  530  is located between and abuts against the second connecting member  508  and the third connecting member  902 , so as to prevent a working fluid (e.g. cooling liquid) from leaking out of the pump  50  and the external device  90 . 
     As mentioned in the above, since the first opening and the second opening of each pump are equipped with the first connecting member and the second connecting member, respectively, for connecting other pumps, the invention allows a user to connect a plurality of pumps in series according to the needed flow rate. Specifically, the invention may design the first connecting member and the second connecting member to be a couple of male and female quick connectors, such that the user may attach/detach the pumps to/from each other more rapidly and conveniently. Furthermore, the invention may dispose the electrical pad on the connecting member or around the first opening/second opening, so as to save circuit layout space for the pump. Still further, the invention may dispose the sensor in the pump to sense the flow rate, the pressure and/or the temperature. Moreover, the invention may dispose the light emitting unit at the periphery of the pump to generate specific visual effect. In addition, the invention may dispose the third connecting member on the external device such as liquid cooling head, radiator, and so on and design the third connecting member to be a male quick connector or a female quick connector, such that the pump of the invention may also be attached to the external device according to practical applications, so as to form the liquid cooling system. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.