Electric compressor

Abstract: To provide an electric compressor with improved workability to connect an end of a stator winding with fastening terminals so that electrical connection can be established between the stator winding and the sealed terminal. The electric compressor includes lug terminal strips to be connected electrically to ends of lead wires each covered with an insulating tube, and fastening terminals connected through the lug terminal strips to the sealed terminal for supplying power to the electric elements, the lug terminal strips manufactured with press molding each including a pair of conductor pressing portions, a cylindrical portion formed on one side of the conductor pressing portions, and a pair of insulating film fixing portions formed on the other side of the conductor pressing portions so that the fastening terminal can be connected to the cylindrical portion by pressing the conductor pressing portions onto the stator winding and fixing the insulating film fixing portions to the insulating tube with pressure welding.

Description: This invention relates to an electrical connector for connecting the end of a stator winding of a compressor used for a refrigerating cycle in refrigerators or air conditioners and to a compressor incorporating such an electrical connector. In a conventional electric-compressor, the sealed terminal used as an input terminal for AC power to be supplied to the electric elements and a stator winding constituting part of the electric elements are generally connected by three lead wires. Such a connecting structure between the electric elements and the sealed terminal is disclosed, for example, in Japanese Utility Model Publication No. 4-14452 (H02K5/22), from which it is known to provide an electrical connector for connecting the end of a stator winding of a compressor to a sealed terminal for supplying power to the compressor, the connector comprising a lug terminal electrically connectable to the end of the stator winding and having a cylindrical portion electrically connectable to a fastening terminal for electrically connecting the lug terminal to the sealed terminal. In such a structure, however, a unit price of cylindrical member is expensive. There is also a limit in external size of cylindrical member due to a limited size in possible pressure welding area on the fastening terminal, resulting in limitations on size or number of the stator windings to be fixed by pressure welding. To solve the above problems, for example, Japanese Utility Model Publication No. 4-128058 (H02K3/38) teaches a connecting structure in which conductive relay members are each interposed between the fastening terminal and the end of the lead wire so that electrical connection can be established by inserting a core of the lead wire into a concave portion formed in each of the relay members. Although the above structure can solve such problems as arise in the former publications, the relay members are irregular in size because they are manufactured by drawing, and this makes it difficult to solder the end of the lead wire in the concave portion. Accordingly, another problems arises that the relay members are unsuitable for automating the solder joint process. It is an object of the present invention to overcome or substantially alleviate the problems with conventional connectors described above. An electrical connector for connecting the end of the stator winding of a compressor to a sealed terminal according to the present invention is characterised in that the lug terminal includes a pair of conductor pressing portions and a pair of insulating tube fixing portions formed on one side of the conductor pressing portions, the arrangement being such that the lug terminal is connected to an end of the stator winding by removing the insulating tube covering the end of the stator winding to form an exposed wire end and inserting the exposed wire end into the lug terminal such that it lies within the cylindrical portion, pressing said conductor pressing portions onto the exposed wire end and pressure welding the insulating tube fixing portions to the insulating tube, the exposed wire end being electrically connected to the cylindrical portion by solder which is allowed to substantially fill and solidify within the cylindrical portions before the cylindrical portion (28) is electrically connected to the fastening terminal (33). The above and other objects and features of the invention are apparent to those skilled in the art from the following preferred embodiments thereof when considered in conjunction with the accompanied drawings, in which: Figure 1 is a longitudinal sectional and side view of an electric compressor according to the present invention; Figure 2 is a plan view of electric elements included in the electric compressor according to the present invention; Figure 3 is an enlarged view of wiring portion of a stator winding included in the electric compressor according to the present invention; Figure 4 is a perspective view of a lug terminal strip; Figure 5 is a perspective view of another lug terminal strip; Figure 6 is a perspective view of still another lug terminal strip; and Figure 7 is a perspective view of yet another lug terminal strip. Referring now to the drawings, a description will be made in detail with respect to a first embodiment of the present invention. Figure 1 is a longitudinal sectional and side view of an electric compressor 1 of the present invention. In Figure 1, the electric compressor 1 is a sealed type electric compressor used for a refrigerating cycle in refrigerators or air conditioners, having a single sealed container 2 in which electric elements 3 and compressive elements 4 are provided on the upper side and the lower side, respectively. The electric elements 3 and the compressive elements 4 are coupled by a rotating shaft 5 having a penetrating hole 5a provided therethrough along an axial direction. The electric elements 3 include a stator core 6, a rotor 7, an end ring 8 and a balance weight 10 provided on the rotor 7, and an end ring 9 and a balance weight 11 provided under the rotor 7. The compressive elements 4 include a cylinder 12 pressed into the sealed container 2 under pressure, an upper frame body 15 and a lower frame body 16 operative to close openings of the cylinder 12, bearing portions 13 and 14 respectively provided on the frame body 15 and under the frame body 16, a roller 17 put externally in an eccentric portion 5b of the rotating shaft 5 so as to rotate eccentrically within the cylinder 12, and a vane (not shown) the tip of which is pressed onto the roller 17 at all times so as to divide the inside of the cylinder 12 into a high pressure side and a low pressure side. A sealed terminal 19 is attached to the inside of the sealed container 2 with its sealing performance held. A stator winding 20 inserted into the stator core 6 is connected to the sealed terminal 19, as described later, through lead wires 21 extending from the end thereof so that electric power can be supplied from the outside of the sealed container 2 to the stator winding 20 through the sealed terminal 19 and the lead wires 21. Next, Fig. 2 is a plan view of the electric elements 3 and Fig. 3 is an enlarged view of the lead wires 21 extending from the stator winding 20, where the lead wires 21 are three in number. The stator winding 20 is formed such that an external surface of an unillustrated core is covered with enamel coating 22. The enamel coating 22 is then stripped off at the end of the lead wires 21 by a wire grinding machine or with high frequency heating, making the core bare. The lead wires 21, which is covered with an insulating tube 23 such as made of a polyester film or Teflon, are cut off with a prescribed size for the purposes of insulation, protection and reinforcement in flexural strength of the lead wires 21 to the breakage of the stator winding 20. Indicated by reference numeral 24 is a lug terminal strip molded by pressing a metal plate such as made of brass, phosphor bronze, aluminum or other materials having conductivity corresponding to the above metals. The lug terminal strip is constituted in plural numbers as a series of terminals coupled with a serial terminal joint 26 shown in Fig. 4. Each of the lug terminal strips 24 includes a pair of conductor pressing portions 27-27 projecting in the central portion, a cylindrical portion 28 formed into a roll shape on one side of the conductor pressing portions 27-27, a pair of conductor soldering portions 29-29 projecting on the other side of the conductor pressing portions 27-27, and a pair of insulating film fixing portions 31-31 projecting on the other side of the conductor soldering portions 29-29. The conductor pressing portions 27-27, the conductor soldering portions 29-29, and the insulating film fixing portions 31-31 project so that opposite sides can together describe a V-like shape. On the other hand, the cylindrical portion 28 is formed into a bored roll with a slit 32 in a butted line. Indicated by reference numeral 33 is a fastening terminal (flag-shaped terminal) one end of which forms a flag-shaped portion 34 to be fitted into the sealed terminal 19. In connecting the lead wire 21, the lug terminal strip 24 and the fastening terminal 33 with each other, the lead wire 21 is first inserted into the lug terminal strip 24 from the side of the insulating film fixing portions 31-31 of the lug terminal strip 24 in the condition that the lug terminal strip 24 is constituted in plural numbers as a series of terminals as shown in Fig. 4. The core of the lead wire 21 then reaches the conductor pressing portions 27-27 and the conductor soldering portions 29-29, while the end of the insulating tube 23 is positioned in a line between the insulating film fixing positions 31-31. Next, the conductor pressing portions 27-27, the conductor soldering portions 29-29, and the insulating film fixing portions 3131 are simultaneously fastened such that the conductor pressing portions 27-27 and the conductor soldering portions 29-29 are temporary pressed onto the core, and the insulating film fixing portions 31-31 are fixed to the insulating tube 23 with pressure welding. In this condition, the lug terminal strip 24 is separated from the serial terminal joint 26 to form a single unit. The cylindrical portion 28 formed at the end of the lug terminal unit is then immersed in a solder bath to inject the melted solder thereinto while soldering the conductor pressing portions 27-27 and the conductor soldering portions 29-29 at the same time, making sure of sufficient sectional area and strength for the pressing portions of the lug terminal strip 24. In this case, a slit 32 is formed on the cylindrical portion 28 so that the cylindrical portion 28 can be smoothly filled with the melted solder. Finally, the fastening terminal 33 is pressed into the cylindrical portion 28. As discussed above, the present invention allows soldering of the conductor pressing portions 27-27 and the conductor soldering portions 29-29 at the same time by injecting the melted solder into the cylindrical portion 28 after fixing the lead wire of the stator winding 20 to the conductor pressing portions 27-27 with pressure welding. The present invention also allows fixing the insulating film fixing portions 31-31 to the insulating tube 23 with pressure welding simultaneously when pressing the conductor pressing portions 27-27 onto the core. Accordingly, connection work between the lead wires 21 and the lug terminal strips 24 can be remarkably improved on the whole. In particular, the lug terminal strips 24 are molded as a series of terminals coupled with the serial terminal joint 26 by pressing a metal plate as mentioned above, and this allows automating the connection process with the stator winding and the like. Next, Fig. 5 shows another embodiment of lug terminal strip 24. In this case, the conductor soldering portions 29-29 of Fig. 4 are eliminated and the insulating film fixing portions 31-31 spread wide on the other side of the conductor pressing portions 27-27. In still another lug terminal strip 24 shown in Fig. 6, the slit 32 is formed in plural numbers on the cylindrical portion 28 of the lug terminal strip 24 of Fig. 5. Further, Fig. 7 shows yet another lug terminal strip 24, in which no slit 32 is formed on the cylindrical portion 28 of the lug terminal strip 24 of Fig. 5. These alternatives may be selected properly as required. As described in detail above, according to the present invention, the lug terminal strips are interposed between the end of the stator winding covered with the insulating tube and the fastening terminals, the lug terminal strips each including a pair of conductor pressing portions, a cylindrical portion formed on one side of the conductor pressing portions, and a pair of insulating film fixing portion formed on the other side of the conductor pressing portions so that the fastening terminal can be connected to the cylindrical portion by pressing the conductor pressing portions onto the stator winding and fixing the insulating film fixing portions to the insulating tube with pressure welding. For this reason, the insulating film fixing portions can be fixed to the insulating tube with pressure welding simultaneously when pressing the conductor pressing portions onto the stator winding, and this makes it possible to ease connection work between the end of the stator winding and the lug terminal strips, resulting in a remarkable improvement in connection work between the end of stator winding and the fastening terminals. In particular, the lug terminal strips are manufactured with press molding, and this allows forming a series of terminals coupled with a serial terminal joint, thereby automating the connection process with the stator winding and the like. Further, the conductor pressing portions (and the conductor soldering portions) can be soldered simultaneously by injecting the melted solder into the cylindrical portion after pressing the stator winding into the conductor pressing portions, and this makes it possible to remarkably improve the workability to connect the end of the stator winding with the lug terminal strips on the whole. Furthermore, the cylindrical portion can be smoothly filled with melted solder through the slit or slits formed on the cylindrical portion, resulting in a further improvement in connection work between the end of the stator winding and the lug terminal strips.

Claims: An electrical connector for connecting the end of a stator winding (20) of a compressor (1) to a sealed terminal (19) for supplying power to the compressor (1), the connector comprising a lug terminal (24) electrically connected to the end of the stator winding (20) and having a cylindrical portion (28) electrically connectable to a fastening terminal (33) for electrically connecting the lug terminal (24) to the sealed terminal (19) characterised in that the lug terminal (24) includes a pair of conductor pressing portions (27) and a pair of insulating tube fixing portions (31) formed on one side of the conductor pressing portions (27), the arrangement being such that the lug terminal (24) is connected to an end of the stator winding (20), the insulating tube (23) covering the end of the stator winding (20) is removed to form an exposed wire end, the exposed wire end is inserted into the lug terminal (24) such that it lies within the cylindrical portion (28), said conductor pressing portions (27) being pressed onto the exposed wire end by pressure welding the insulating tube fixing portions (31) to the insulating tube (23), the exposed wire end being electrically connected to the cylindrical portion (28) by solder which is allowed to substantially fill and solidify within the cylindrical portion (28) before the cylindrical portion (28) is electrically connected to the fastening terminal (33). An electrical connector according to claim 1 wherein at least one slit (32) is formed in the cylindrical portion. An electrical connector according to claim 1 or claim 2 including a fastening terminal (33) configured to receive the cylindrical portion (28) of the lug terminal (24) to electrically connect the lug terminal (24) to the fastening terminal (33). A compressor incorporating an electrical connector as defined in any of claims 1 to 3.

Inventors: KURAMOTO EIJI, MURATA EIICHI, OYAMA KIICHI, YAMANOI MASAAKI, KURAMOTO, EIJI, MURATA, EIICHI, OYAMA, KIICHI, YAMANOI, MASAAKI
Applicants: SANYO ELECTRIC CO, TOMITA ELECTRIC CO LTD, SANYO ELECTRIC CO., LTD., TOMITA ELECTRIC CO., LTD.
Application year: 1996
Main classification: H01R4
IPC codes: H02K5, F04C23, H01R13, H01R4