Patent Publication Number: US-6705892-B2

Title: Terminal assembly for compressor

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a compressor, and more particularly, to a terminal assembly for supplying electric power to a compressor. 
     2. Description of the Prior Art 
     Compressors are used for compressing a working fluid such as a refrigerant and can be classified into a reciprocating compressor and a linear compressor according to an operating manner of a motor unit providing power for the compression of the working fluid. The reciprocating compressor is operated in such a manner that a crankshaft is rotated by means of rotation of the motor unit and the rotation of the crankshaft is converted into a linear reciprocating motion of a piston via a connecting rod or the like. The linear compressor is operated in such a manner that the motor unit itself performs a linear reciprocating motion to directly drive the piston. 
     Meanwhile, electric power should be supplied from the outside to the motor unit in order to drive such a compressor. FIG. 1 shows a general configuration of the reciprocating compressor for supplying external electric power to the compressor. Referring to the figure, a protector  12  is installed on an outer surface of a lower housing  10  constituting a part of a hermetic housing. The protector  12  is generally mounted on the lower housing  10  by means of spot welding. A terminal assembly  20  to be described later is mounted on the protector  12 . A plurality of terminals  13  are provided at the center of the protector  12 . The terminals  13  penetrate the lower housing  10  and are then electrically connected to additional connectors within the lower housing  10 . 
     The terminal assembly  20  mainly comprises a terminal board  21 , a positive temperature coefficient (PTC) unit  25  inserted into and mounted on the terminal board  21 , and a fuse unit  29  inserted into and mounted on the terminal board  21 . 
     For reference, the PTC unit  25  is constructed to include its own terminals and a PTC device interposed between the terminals so that an electric current can be interrupted according to whether the PTC device operates or not. The PTC device is configured to operate in the following manner. When the electric current flows in the PTC device, the device radiates heat and its resistance is increased. Such an increase of the resistance results in interruption of the electric current. When the temperature of the PTC device is lowered after the interruption, its resistance is decreased and the electric current flows again within a predetermined time. 
     The terminal board  21  is formed with a first mounting portion  22  and a second mounting portion  24  on which the PTC unit  25  and the fuse unit  29  are mounted, respectively. The first and second mounting portions  22 ,  24  are formed to penetrate the terminal board  21  so that portions of the PTC unit  25  and the fuse unit  29  can penetrate the terminal board and then be connected to the terminals  13 , respectively. An additional cover (not shown) is installed on the terminal board  21  to shield the PTC unit  25  and the fuse unit  29 . 
     In the meantime, there has been recently provided a terminal assembly capable of being used commonly for the reciprocating compressor and the linear compressor. That is, as shown in FIGS. 2 a  to  3   b , a terminal frame  31  constructed to be seated in the protector  12  is provided with a connector  33  electrically connected to the terminals  13 . Connection wires  34  for connecting the terminals  13  and the outside are connected to and installed in the connector  33 . The PTC unit, the fuse unit and the like are seated in the terminal frame  31 . 
     Further, a cover  40  is used to shield the terminal frame  31 . An inner surface of the cover  40  is formed with a restriction boss  42  for maintaining a state where the connector  33  is connected to the terminals  13 . The position of the restriction boss  42  approximately corresponds to the center of the connector  33 , as well shown in FIG. 2 a.    
     Meanwhile, the terminal assembly  30  can be commonly used even for the linear compressor. FIGS. 2 b  and  3   b  show a state where the terminal assembly  30  is used for the linear compressor. 
     Since the positions of the terminals  13  are changed in the linear compressor, the mounted position of the connector  33  is also changed. That is, as shown in FIG. 2 b , the connection wires  34  of the connector  33  extend out from an upper left portion of the terminal frame  31  and then lead downward. In other words, although the direction in which the terminal frame  31  of the terminal assembly  30  is mounted is the same, the direction of the connector  33  provided in the terminal frame  31  is changed. 
     However, there is the following problem in the aforementioned prior art. 
     One kind of terminal assembly  30  can be commonly used for the reciprocating compressor and the linear compressor in the prior art. If the terminal assembly  30  is used for the linear compressor, however, only the direction of the connector  33  installed in the terminal assembly is changed and thus the position of the restriction boss  42  for preventing detachment of the connector  33  is changed. 
     Therefore, in case of the linear compressor, if an external force is exerted to the connection wires  34  extending from the connector  33  or an impact generated upon transport of the compressor is exerted thereto, the connector  33  escapes from the terminals  13  as shown in FIG. 3 b . This is because the restriction boss  42  dose not correctly restrict the center of the connector  33  but restrict a position offset from the center of the connector  33  as shown in FIG. 2 b.    
     In such a state, since the connection wires  34  are not electrically connected to the terminals  13 , there is a problem in that the compressor cannot be started. 
     SUMMARY OF THE INVENTION 
     The present invention is conceived to solve the aforementioned problem in the prior art. An object of the present invention is to provide a terminal assembly of which a connector can be firmly installed therein even when being commonly used for a reciprocating compressor and a linear compressor. 
     According to an aspect of the present invention for achieving the object, there is provided a terminal assembly for a compressor, comprising a protector with terminals electrically connected to parts within the compressor; a connector mounted on the terminals for performing electrical connection between the terminals and connection wires; a terminal frame which is mounted on an outer surface of a hermetic housing of the compressor and in which the connector is seated; and a cover which is mounted on the terminal flame for shielding parts installed in the terminal frame and has restriction bosses for restricting detachment of the connector. At least two restriction bosses are formed at a predetermined interval on the cover so as to press down opposite ends of the connector even when the connector is placed at a rotated position within the terminal frame. 
     The interval between the restriction bosses may be smaller than a width between the opposite ends of the connector. 
     When the cover is mounted on the terminal frame, the restriction bosses may come into contact with the connector at a maximum length of the restriction bosses. 
     According to the terminal assembly for the compressor of the present invention constructed as such, there is an advantage in that even while one kind of terminal assembly is commonly used for compressors in which the positions of terminals are set to be different from each other, an installation state of the terminal assembly can be more firmly maintained. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects and features of the present invention will become apparent from the following description of a preferred embodiment given in conjunction with the accompanying drawings, in which: 
     FIG. 1 is an exploded perspective view showing a lower housing of a reciprocating compressor and a configuration of a terminal assembly mounted thereto in the prior art; 
     FIG. 2 a  is a view schematically showing a configuration in which another conventional terminal assembly is mounted to the reciprocating compressor; 
     FIG. 2 b  is a view schematically showing a configuration in which the conventional terminal assembly of FIG. 2 a  is mounted to a linear compressor; 
     FIG. 3 a  is a sectional view schematically showing the structure of the terminal assembly shown in FIG. 2 a;    
     FIG. 3 b  is a sectional view schematically showing the structure of the terminal assembly shown in FIG. 3 a;    
     FIG. 4 is a sectional view schematically showing the structure of a terminal assembly for a compressor according to the present invention; 
     FIG. 5 a  is a view schematically showing a configuration in which the terminal assembly for the compressor according to the present invention is mounted to the reciprocating compressor; and 
     FIG. 5 b  is a view schematically showing a configuration in which the terminal assembly for the compressor according to the present invention is mounted to the linear compressor. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, a preferred embodiment of a terminal assembly for a compressor according to the present invention will be described in detail with reference to the accompanying drawings. 
     FIG. 4 shows a sectional view of the structure of the terminal assembly for the compressor according to the present invention, FIG. 5 a  is a view schematically showing a configuration in which the terminal assembly for the compressor according to the present invention is mounted to a reciprocating compressor; and FIG. 5 b  is a view schematically showing a configuration in which the terminal assembly for the compressor according to the present invention is mounted to a linear compressor. 
     Referring to these figures, the terminal assembly  60  according to the embodiment of the present invention comprises a terminal frame  61 , a connector  70  and a cover  80 . A variety of parts such as a PTC unit and a fuse unit (not shown) are mounted in the terminal frame  61 . 
     The terminal assembly  60  of the embodiment is mounted on terminals  50  that are installed to penetrate a hermetic housing constituting an external appearance of the compressor. Of course, a protector surrounding the terminals  50  is mounted to the hermetic housing. 
     The terminal frame  61  constituting the terminal assembly  60  is formed to be seated in the protector. The connector  70  is placed on the terminal frame  61 . An installation position of the connector  70  can be changed within the terminal frame  61 . The installation position is determined according to positions of the terminals  50  that depend on the kinds of compressors. 
     For example, in case of the reciprocating compressor in which the respective terminals  50  are arranged at vertexes of an inverted triangle as shown in FIG. 5 a , the connector is installed so that connection wires  72  extend directly toward a lower portion of the terminal frame  61 . On the other hand, in case of the linear compressor in which the respective terminals  50  are arranged at vertexes of a triangle inclined leftward at a predetermined angle as shown in FIG. 5 b , the connector is installed so that the connection wires  72  extend out from an upper left portion of the connector and then lead to the lower portion of the terminal frame. 
     Such a connector  70  electrically connects the terminals  50  to the connection wires  72  so that control signals can be transmitted out of and into the compressor and external electric power for driving the compressor can be supplied into the compressor. 
     Further, the PTC unit and the fuse unit in addition to the connector  70  are mounted in the terminal frame  61 . 
     Meanwhile, the cover  80  is mounted on the terminal frame  61 . The cover  80  functions to shield the terminal frame  61 . Such a cover  80  may be mounted on the terminal frame  61  by means of an additional elastic structure formed in the cover itself or separate fastening screws. 
     An inner surface of the cover  80  is formed with restriction bosses  82 ,  83  for restricting play or movement of the connector  70  to prevent the connector  70  from being detached from the terminals. The restriction bosses  82 ,  83  are formed to be spaced apart from each other by a predetermined interval. That is, the restriction bosses  82 ,  83  are formed at the predetermined interval in a generally longitudinal direction of the connector  70  to restrict the detachment of the connector  70  even though the direction in which the connector  70  is mounted on the terminals  50  is changed. At this time, the interval between the restriction bosses  82 ,  83  should be shorter than the length of the connector  70 . 
     Further, the restriction bosses  82 ,  83  are arranged in an up and down direction in the reciprocating compressor shown in FIG. 5 a . In the present embodiment, the restriction bosses  82 ,  83  are formed such that there is a predetermined gap between the tips of the restriction bosses and the connector  70  when the cover  80  is mounted on the terminal frame  61 . However, it is not always necessary to have the predetermined gap therebetween. The length of the restriction bosses  82 ,  83  may be designed so that they can come into close contact with a surface of the connector  70 . 
     For reference, although two restriction bosses  82 ,  83  are formed in the present embodiment, two or more restriction bosses may be formed to restrict the detachment of the connector  70 . The formation of two or more restriction bosses can be usefully employed in a case where the installation direction of the connector  70  is changed variously. 
     Hereinafter, the operation of the terminal assembly for the compressor according to the present invention constructed as such will be described in detail. 
     The present invention can effectively prevent the detachment of the connector  70  even though the installation direction of the connector  70  varies, by forming the plurality of restriction bosses  82 ,  83  on the inner surface of the cover  80 . 
     That is, in the case where the terminal assembly  60  is mounted on an outer surface of the hermetic housing of the reciprocating compressor as shown in FIG. 5 a , the connector  70  is installed so that the connection wires  72  extend downward and out of the terminal assembly  60 . 
     At this time, as the cover  80  is mounted on the terminal frame  61 , the restriction bosses  82 ,  83  are placed at positions corresponding to upper and lower ends of the connector  70 . In such a state, the connector  70  is restricted from being detached by the restriction bosses  82 ,  83 . 
     On the other hand, in the case where the terminal assembly  60  is mounted on an outer surface of the hermetic housing of the linear compressor as shown in FIG. 5 b , the connector  70  is installed so that the connection wires  72  extend out from the upper left portion of the connector and toward the lower portion of and out of the terminal assembly  60 . 
     The reason that the connector  70  should be installed in such a way is that the arrangement of the terminals  50  on the outer surface of the hermetic housing of the linear compressor is different from that of the reciprocating compressor. That is, as shown in FIG. 5 b , the connector  70  is mounted on the terminals  50  so that the connection wires  72  of the connector  70  are placed at a relatively upper position. This is because the same terminal assembly  60  is commonly used for the reciprocating compressor and the linear compressor. 
     At this time, (assuming that a portion of the connector  70  to which the connection wires  72  are connected is a lower end thereof,) the restriction bosses  82 ,  83  restrict positions of the connector  70  corresponding to one side end portion of the upper end of the connector  70  and a diagonal end portion of the lower end of the connector  70 . 
     Therefore, if the connection wires  72  are pulled out, the restriction boss  82  positioned at an upper position in the figures restricts the connector  70 . Thus, the connector  70  is prevented from being detached from the terminals  50 . The upper end of the connector  70  is prevented from being detached from the terminals  50  by the restriction boss  83 . 
     The terminal assembly for the compressor according to the present invention described in detail above has the following effects. 
     Since at least two restriction bosses for restricting the detachment of the connector are formed on the cover of the terminal assembly of the present invention, the restriction bosses restrict the connector from being detached from the terminals regardless of the installation direction of the connector. 
     Therefore, even while the terminal assembly can be commonly used for the reciprocating compressor and the linear compressor of which the installation directions of the connector are different from each other, the state where the connector provided in the terminal assembly is connected to the terminals can be firmly maintained. 
     According to the present invention, there are advantages in that production costs and part management costs can be reduced owing to part sharing, and the operation reliability of the compressor can be improved owing to the firm connection state of the connector.