Abstract:
Disclosed are a resistor, a heat dissipater and a combinatory device of the resistor and the heat dissipater, and relates to the field of power electronics. The resistor is cylindrical, and comprises a metal end, an insulating part, a casing, metal bars, a resistor wire, thermally conductive insulating fillers and a metal connection mechanism. The metal connection mechanism of the resistor and the heat dissipater are connected by means of direct contact. The structure and the connection method can shorten the length of the resistor, completely insulate the electrical circuits of the resistor from the possible leakage of the water inlet- and outlet-pipe of the heat dissipater, and enable the combinatory device of the resistor and the heat dissipater to be structurally more compact and the connections thereof cleaner.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a technical field of power electronics and power system, in particular relates to a resistor, a heat dissipater and a combinatory device of the resistor and the heat dissipater. 
       BACKGROUND 
       [0002]    With the maturity of high-power power electronics technology and the demands on power system development, using high-voltage high-power resistors is necessary in more and more scenes. 
         [0003]    Presently high-power resistors applied in domestic and abroad suffer very high power dissipation in operation of resistors, thus radiating methods to resistors must be designed. Presently there are two kinds of common radiating methods. The first method is cooling resistor wires by immersing resistor wires in cooling fluid directly. 
         [0004]    The disadvantages thereof are vulnerably occurring chemical reactions, such like ionization and rustiness, in case resistors are under current for a long-time running, which affects the reliability of resistors and circulating cooling circuits enoiiiiously. The second method as shown in  FIG. 1 : reference sign  1  in drawings represents a heat dissipater, and reference signs  2 ,  3  represent respectively an inlet and outlet. Heat of the resistor is transferred to the metal heat dissipater via heat transfer medium, and then fluid cooling proceeds via the heat dissipater. The disadvantages thereof are that, when the resistor is mounted in the heat dissipater, an electrical tail wire  20  on one side of the resistor and an inlet- and outlet-pipe  21  will affect each other mutually. Meanwhile when for the inlet- and outlet-pipe  21  occurs weeping or other malfunctions, it may cause electrical damages, which reduces the reliability of the system enormously; moreover the one end of the resistor closing to the inlet- and outlet-pipe  21  of the heat dissipater can stretch out of the heat dissipater for a relatively long distance, which causes incompact structure and space waste of the combinatory device of the resistor and the heat dissipater; in occasions where resistors and heat dissipaters are applied frequently, the electrical tail wires closing to the one end of the inlet- and outlet-pipe of the heat dissipater make the wiring irregular. 
       SUMMARY OF THE INVENTION 
       [0005]    The objective of the present invention is to provide a resistor, a heat dissipater and a combinatory device of the resistor and the heat dissipater, in order to accomplish a complete isolation between an electrical circuit and a cooling branch circuit of the resistor, a compact structure of the combinatory device of the resistor and the heat dissipater, and a concise electrical connection of the resistor. 
         [0006]    To achieve the objective above, the technical solutions of the present invention are: 
         [0007]    A resistor, which is cylindrical, and comprises a metal end  10 , an insulating part  11 , a casing  12 , a first metal bar  15   a,  a second metal bar  15   b,  a resistor wire  13 , thermally conductive insulating fillers  14 , a metal connection mechanism  18 , the relationships of the parts are as below: a cavity of the casing  12  in which the resistor wire  13  is placed, and is filled with the thermally conductive insulating fillers  14 ; both ends of the resistor wire  13  are connected respectively to the first metal bar  15   a  and the second metal bar  15   b  which stretch into the casing  12 ; the other end of the second metal bar  15   b  is connected to the metal end  10  as one head end of the resistor, the other end of the first metal bar  15   a  is reliably connected to the metal connection mechanism  18  as the other head end of the resistor, the metal connection mechanism  18  is connected to an one end of the casing( 12 ) with equal electric potentials; spaces between the inner diameter of one end of the casing  12  and the second metal bar  15   b  exposing out of the casing  12  and the metal end  10  are sealed with insulating material  11 . The metal connection mechanism  18  comprises a metal end cap  16  and a metal mounting ring  17 , the metal end cap  16  is connected with one end of the casing  12 . The metal connection mechanism  18  comprises a metal end cap  16  and a thread  19  on the outer diameter of the end cap, the metal end cap  16  is connected with one end of the casing  12 . 
         [0008]    The other end of the second metal bar  15   b  is electrically connected with the metal end  10  by welding. 
         [0009]    The metal end  10  is provided with a thread structure used for connecting with a tail wire. The metal connection mechanism  18  is electrically connected to the first metal bar  15   a  by one of the following methods: 
         [0010]    welding or matched thread screwing. 
         [0011]    The space between the inner diameter of one end of the casing  12  which is connected to the metal connection mechanism  18 and the first metal bar  15   a  exposing out of the casing  12  is filled with the insulating materials. 
         [0012]    The metal end cap  16  is electrically connected to the metal mounting ring  17  by one of the following methods: 
         [0013]    welding, thermal shrinkage locking or matched thread screwing. 
         [0014]    A heat dissipater which comprises an inlet- and outlet and at least a resistor hub, wherein the resistor hub is provided with a fixing mechanism, which is matched to the metal connection mechanism  18  of the resistor, the fixing mechanism is matched to the metal connection mechanism  18  so as to accomplish the mechanical fixation of the resistor on the heat dissipater and the electrical connection between the resistor and the heat dissipater. The fixing mechanism comprises screw holes and threads which are matched to metal screws of the metal mounting ring  17  of the resistor. 
         [0015]    The fixing mechanism comprises screw holes and threads which are matched to a thread  19  on the outer diameter of the end cap of the resistor. 
         [0016]    The device comprises the resistor of any one of claims  1 - 8  and the heat dissipater of any one of claims  9 - 11 , wherein in each heat dissipater at least one resistor is mounted, and the resistor is mechanically fixed on the heat dissipater by metal connection mechanism  18  to accomplish the electrical connection. 
         [0017]    By applying the technical solutions above, the present invention can at least achieve the following advantageous effects: 1) shortening the length of the resistor under conditions of constant resistance and sectional area; 
         [0018]    2) completely insulate the electrical circuits from the cooling branch circuit, to avoid electrical malfunctions caused by leakage of the inlet- and outlet-pipe of the heat dissipater; 
         [0019]    3) enable the combinatory device of the resistor and the heat dissipater to be structurally more compact, and saving space; 
         [0020]    4) needless of a terminal electrical lead-out wire closing to one end of the inlet- and outlet-pipe of the heat dissipater, so as to make electrical connection cleaner. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  shows a structure schematic diagram of a combinatory device of a resistor and a heat dissipater of the prior art; 
           [0022]      FIG. 2  shows a structure scheme of an embodiment of a single resistor of the present invention; 
           [0023]      FIG. 3  shows a structure scheme of an embodiment of a terminal metal connection mechanism of the present invention; 
           [0024]      FIG. 4  shows a structure scheme of an embodiment of a combinatory device of a resistor and a heat dissipater of the present invention; 
           [0025]      FIG. 5  shows a structure scheme of another embodiment of a single resistor; 
           [0026]      FIG. 6  shows a structure scheme of another embodiment of a teii iinal metal connection mechanism of the present invention; 
           [0027]      FIG. 7  shows a structure scheme of an embodiment of a combinatory device of a resistor and a heat dissipater; 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    The technical solution of the present invention is further explained as below with reference to the accompanying drawings and detailed description. 
         [0029]    A structure scheme of an embodiment of a single resistor of the present invention is shown as in  FIG. 2 , wherein the resister comprises a metal end  10 , an insulating part  11 , a casing  12 , a first metal bar  15   a  and a second metal bar  15   b,  a resistor wire  13 , thermally conductive insulating fillers  14  and a metal connection mechanism  18 . The casing  12  is normally made of metal materials, a cavity thereof where the resistor wire  13  is placed, and is filled with thermally conductive insulating fillers  14 ; both ends of the resistor wire  13  are connected respectively with one end of the first metal bar  15   a  stretching into the casing  12  and one end of the second metal bar  15   b.  The other end of the second metal bar  15   b  is connected with the metal end  10  as a head end of the resistor. A portion of the second metal bar  15   b  is exposing out of the casing  12 ; the other end of the first metal bar  15   a  is reliably connected with the metal connection mechanism  18  as the other head end of the resistor; meanwhile the metal connection mechanism  18  is connected with one end of the casing  12  (seamless connection could be achieved) with equal electric potentials; spaces between the inner diameter of one end of the casing  12  and the second metal bar  15   b  exposing out of the casing  12  and the metal end  10  are sealed with the filling insulating materials  11 ; the insulating part  11  is normally manufactured epoxy casting, to accomplish electrical isolation of the second metal bar  15   b  from the casing  12 . 
         [0030]    In the above-mentioned embodiment, the electrical connection between the other end of the second metal bar  15   b  and the metal end  10  can be accomplished by means of welding. 
         [0031]    In the above-mentioned embodiment, the metal end  10  can comprise thread structure, to facilitate connecting with the lead-out wire. In the above-mentioned embodiment, an electrical connection between the metal connection mechanism  18  and the first metal bar  15   a  can be accomplished by one of the following means: welding or matched thread screwing. 
         [0032]    In the above-mentioned embodiment, the space between the inner diameter of one end connected to the metal connection mechanism  18  of the casing  12  and the first metal bar  15   a  exposing out of the casing  12  are filled with insulating materials, as shown in  FIG. 2  that the insulating part  11  between the inner diameter of one end of the casing  12  connected to the metal connection mechanism  18  and the first metal bar  15   a  exposing out of the casing  12 ; the insulating part  11  is normally manufactured by epoxy casting, to accomplish electrical isolation between the first metal bar  15   a  and the casing  12 . 
         [0033]    In the above-mentioned embodiment, the metal connection mechanism  18  can be any one of structures achieving direct contact and connection between one end of the resistor and the heat dissipater. 
         [0034]      FIG. 3  shows a structure scheme of an embodiment of the terminal metal connection mechanism. The metal connection mechanism  18  is consist of a metal end cap  16  and a metal mounting ring  17 . The electrical connection between the metal end cap  16  and the metal mounting ring  17  can be accomplished by means of welding, thermal shrinkage locking, matched thread screwing and so on. The metal end cap  16  is connected with one end of the casing  12  (seamless connection could be achieved). It should be noted that the insulating part  11  between the metal connection mechanism  18  and the thermally conductive insulating fillers  14  (between the inner diameter of one end connected to the metal connection mechanism  18  of the casing  12 and the first metal bar  15   a  stretching out of the casing  12 ) is added for facilitating the manufacture of a resistor, and is not essential for the electrical functions of the resistor of the present invention. 
         [0035]      FIG. 4  is a structure scheme of an embodiment for a combinatory device of a resistor and a heat dissipater of the present invention, wherein the heat dissipater  1  comprises an inlet- and outlet (as respectively shown with reference signs  2 ,  3  in the figure) and at least one resistor hub (there are  6  in the figure, as shown with reference signs  4   a - 9   a  in the figure); there are  6  resistors ( 4 - 9 ) in total, employing the structure shown in  FIG. 2 , and mounted in the heat dissipater  1 . According to practical applications, at least one such resistor can be mounted in the heat dissipater  1 . The resistor hub is provided with a fixing mechanism, which is matched to the metal connection mechanism  18  of the resistor, matching the fixing mechanism with the metal connection mechanism  18  could accomplish the mechanical fixation of the resistor on the heat dissipater and the electrical connection between the resistor and the heat dissipater. As seen from the right side view that the mounting ring  17  of the resistor is fixed on the heat dissipater (the fixing mechanism of the heat dissipater comprises screw holes and threads matched to the metal screws of the metal mounting ring  17  of the resistor) via metal screws ( 4   b - 9   b ). On one hand, it accomplishes the mechanical fixation between the heat dissipater and the resistor. On the other hand, it accomplishes the electrical reliable connection between the heat dissipater and one end of the resistor, so that one end of the resistor and the heat dissipater have equal potentials, and current flowing in the heat dissipater is conducted into one end of the resistor directly. As seen from the front view that after mounting of the resistor in the heat dissipater, there is no any electrical lead-out wire around one end of the inlet- and outlet-pipe of the heat dissipater, so as to avoid the mutual affection of the inlet- and outlet-pipe and the electrical connection wires of the resistor. If proper mechanical processing is made with respect to the ends of the resistor hubs of the heat dissipater  1 , e.g. milling corresponding notches on the ends of the resistor hubs of the heat dissipater  1  according to the shape and the thickness of the metal connection mechanism  18  of the resistor, then the metal connection mechanism  18  of the resistor could be embed in the heat dissipater  1  completely while mounting, so as to make the surface of the metal connection mechanism  18  of the resistor flush to a side surface of the heat dissipater, or only to leave “little bulges” on the side surface of the heat dissipater with a same number as the number of the plugged resistors. It brings better effects in view of electric and esthetics. 
         [0036]    It should be noted that in the practical applications, the number of the resistor hubs comprised in a heat dissipater is not limited to the same mentioned in the above embodiments, but can be varied depending on actual practice. 
         [0037]      FIG. 5  shows a structure scheme of another embodiment of a single resistor of the present invention, wherein the resistor comprises a metal end  10 , an insulating part  11 , a casing  12 , a first metal bar  15   a  and a second metal bar  15   b,  a resistor wire  13 , thermally conductive insulating fillers  14 , and a metal connection mechanism  18 . The casing  12  is normally made of metal materials, a cavity thereof where the resistor wire  13  is placed, and is filled with thermally conductive insulating fillers  14 ; both ends of the resistor wire  13  are connected respectively with one end of the first metal bar  15   a  stretching into the casing  12  and with one end of the second metal bar  15   b.  The other end of the second metal bar  15   b  is connected with the metal end  10  as one end of the resistor. A portion of second metal bar  15   b  is exposing out of the casing  12 . The other end of the first metal bar  15   a  is reliably connected with the metal connection mechanism  18  as the other end of the resistor. Meanwhile the metal connection mechanism  18  is connected with one end of the casing  12  (seamless connection could be achieved) with equal electric potentials; spaces between the inner diameter of one end of the casing  12  and the second metal bar  15   b  exposing out of the casing  12  and the metal end  10  are sealed with the filling insulating material  11 ; the insulating part  11  is normally manufactured by epoxy casting, to accomplish electrical isolation. 
         [0038]    In the above-mentioned embodiment, electrical connection of the other end of the second metal bar  15   b  and the metal end  10  can be accomplished by means of welding. 
         [0039]    In the above-mentioned embodiment, the metal end  10  can comprise a thread structure, to facilitate connecting with the lead-out wire. In the above-mentioned embodiment, an electrical connection between the metal connection mechanism  18  and the first metal bar  15   a  can be accomplished by one of the following means: welding or matched thread screwing. 
         [0040]    In the above-mentioned embodiment, a space between the inner diameter of one end connected to the metal connection mechanism  18  of the casing  12  the first metal bar  15   a  exposing out of the casing  12  is filled with insulating materials, as the insulating part  11  between the inner diameter of one end connected to the metal connection mechanism  18  of the casing  12  and the first metal bar  15   a  exposing out of the casing  12  shown in  FIG. 5 ; the insulating part  11  is normally manufactured by epoxy casting, to accomplish the electrical isolation between the first metal bar  15   a  and the casing  12 . 
         [0041]    In the above-mentioned embodiment, the metal connection mechanism  18  comprises the metal end cap  16  and the thread  19  on the outer surface of the end cap. The end cap  16  is connected with the one end of the casing  12  (seamless connection possible). The resistor is mounted in the heat dissipater via the thread  19  directly, meantime the electrical reliable connection of the one end of the resistor and the heat dissipater is accomplished. 
         [0042]      FIG. 6  shows a structure scheme of another embodiment of the metal connection mechanism at the end of the present invention, the metal connection mechanism  18  comprises the metal end cap  16  and the thread  19  and is mounted in the heat dissipater directly by the thread  19 . There are  6  such resistor ( 22 - 27 ) mounted in the heat dissipater as shown in  FIG. 7 .  FIG. 7  is a structure scheme of an embodiment for a combinatory device of resistors and heat dissipaters of the present invention, wherein a heat dissipater  1  comprises inlet- and outlet (as respectively shown with reference signs  2 ,  3  in the figure.) and at least one resistor hub (there are  6  in the fig., as shown in the fig. with reference signs  4   a - 9   a ); there are  6  resistors ( 22 - 27 ) in total, applying the structure as shown in  FIG. 5 , and mounted in the heat dissipater  1 . According to practical applications in the heat dissipater  1  at least one such resistor can be mounted. The resistor hub is provided with a fixing mechanism, which is matched to the metal connection mechanism  18  of the resistor, matching the fixing mechanism and the metal connection mechanism  18  could accomplish the mechanical fixation of the resistor on the heat dissipater and the electrical connection between the resistor and the heat dissipater. As seen from the right side view that the metal connection mechanism  18  of the resistor is fixed on the heat dissipater (the fixing mechanism of the heat dissipater comprises screw holes and threads matched to the threads  19  on the outer surface of the end cap of the resistor) via the thread. On one hand it accomplishes the mechanical fixation between the heat dissipater and the resistor. On the other hand, it accomplishes the electrical reliable connection between the heat dissipater and one end of the resistor, so that one end of the resistor and the heat dissipater have the equal potentials, and the current flowing in the heat dissipater conducted into one end of the resistor directly. As seen from the front view that after mounting of the resistor in the heat dissipater there is no any electrical lead-out wire around one end side of the inlet- and outlet-pipe of the heat dissipater, so as to avoid the mutual affection of the inlet- and outlet-pipe and the electrical connection wires of the resistor. If proper mechanical processing is made with respect to the ends of the resistor hubs of the heat dissipater  1 , e.g. milling corresponding notches on the ends of the resistor hubs of the heat dissipater  1  according to the shape and the thickness of the metal connection mechanism  18  of the resistor, then the metal connection mechanism  18  of the resistor could be embed in the heat dissipater  1  completely while mounting, so as to make the surface of the metal connection mechanism  18  of the resistor flush to a side surface of the heat dissipater, or only to leave “little bulges” on the side surface of the heat dissipater with a same number as the number of the plugged resistors. It brings better effects in view of electric and esthetics. 
         [0043]    It should be noted that in the practical applications, the number of the resistor hubs comprised in a heat dissipater is not limited to the same mentioned in the above embodiments, but can be varied depending on actual practice. 
         [0044]    Summarized by applying the technical solutions above of the present invention, at least the following advantageous effects can be accomplished: 
         [0045]    1) shortening the length of the resistor under condition of constant resistance and sectional area; 
         [0046]    2) completely insulating the electrical circuits from the cooling branch circuit, to avoid electrical malfunctions caused by leakage of the inlet- and outlet-pipe of the heat dissipater; 3) enable the combinatory device of the resistor and the heat dissipater to be structurally more compact, and saving space; 
         [0047]    4) needless of electrical lead-out wires closing to the end of the inlet- and outlet-pipe of the heat dissipater, so as to make electrical connection cleaner. 
         [0048]    The above-mentioned embodiments are only used for explaining the technical concept of the present invention, but not wherewith for limiting the protection scope of the present invention. All of the technical concepts according to the present invention, or any amendments or improvements based on the technical solutions fall within the scope of the protection of the present invention.