Connector assembly for the windings of a stator of an electric motor

Abstract: A connector assembly, particularly for the windings of a stator (11) of an electric motor (12) which comprises a connector element constituted by a section (14) for anchoring to the electric motor (12) and by a section (15) for the guided and predefined connection of the windings to a complementary part connected to the power supply; the sections are mutually monolithic and the latter section (15) has one or more cavities adapted to accommodate terminals (17) for electrical connection between the stator (11) and the power supply; the connector assembly is characterized in that each one of the terminals (17) is constituted by a laminar body, made of conducting material, which comprises two sections which lie on mutually perpendicular planes; a first one (19) of the sections is shaped so as to form a flap, the free end of which is in turn shaped so as to form two substantially rigid mutually opposite wings which form a slot in which two elastic tabs converge towards the bottom; the tabs are connected in an L-shaped configuration to a corresponding wing, and an electric conductor with insulating sheath can be inserted up to the free end between the elastic tabs, part of the edges of which is sharp. A second one of the sections is shaped so as to form the male element of an electrical connection to a corresponding female terminal.

Description: The present invention relates to a connector assembly which is useful particularly but not exclusively for the windings of a stator of an electric motor. An electric motor conventionally comprises a stator part and an axial shaft which are inside a frame; the rotor is fixed to the shaft, which is supported by bearings. The stator part is usually constituted by a lamination pack on which a plurality of conductors are wound which form the stator windings; their end portions are connected to the mains for power supply. Currently, as soon as the stator winding has been formed, each one of the leads of the conductors is welded to a corresponding conductor of a wiring system. The welding points are then insulated electrically by means of tapes or sleeves. In small- and medium-power electric motors, the leads of the stator windings are connected to a connecting terminal strip. Both methods for connecting the stator leads to the power supply, although performing their intended aim and objects, entail drawbacks. Among these drawbacks, particular mention must be made of an extremely labor-intensive nature, complexity in construction and structural weak points with a high risk of failure especially at the welds, with a consequent risk of shorting. WO 93/05562 discloses a connector assemby for terminating electrodynamic stator coils, according to which the preamble of claim 1 has been defined. FR-2,682,221 discloses a connector which is however not intended for use with the windings of the stator of an electric motor and that is not formed by two sections which lie in two mutually perpendicular planes. GB-A-1,522,863 discloses an electrical connector which is not constituted by two sections arranged in mutually perpendicular planes and that is not intended for windings of the stator of an electric motor. The connector is also not provided with elastic tabs which are formed in a slot of the body of the connector and which converge towards the bottom of the slot. The aim of the present invention is to provide a connector assembly, particularly for the windings of a stator of an electric motor, which ensures a connection thereof to the power supply which is always optimum, without risks of failure and shorting, and at the same time is considerably simple constructively and easy to mass-manufacture. Accordingly, an object of the present invention is to provide a connector assembly in which the cables are seated safely and precisely even in mass-manufacture assemblies. Another object of the present invention is to provide a connector assembly in which connection to the leads of the cables arriving from the power supply is also particularly simple and quick to perform. Another object of the present invention is to provide a connector assembly whose costs are competitive with respect to conventional ones. Another object of the present invention is to provide a connector assembly which can be manufactured with conventional technologies and whose assembly does not require a specialized work force. Another object of the present invention is to provide a connector in which it is possible to easily perform any maintenance operations for replacing cables and which offers substantially total safety for the operating personnel. This aim, these objects and others which will become apparent hereinafter are achieved by a connector assembly for the windings of a stator of an electric motor, as defined in claim 1. Further characteristics and advantages of the present invention will become apparent from the following detailed description of three embodiments thereof and of corresponding variations, illustrated only by way of non-limitative example in the accompanying drawings, wherein: figure 1 is a partially sectional projection view of a connector assembly according to the invention, in a first embodiment; figure 2 is another orthographic projection view of the assembly of figure 1; figure 3 is another orthographic projection view of the assembly of figure 1 in the operating condition; figures 4 and 5 are two different orthographic projection views of a detail of the assembly of figure 1; figures 6 and 7 are two different orthographic projection views of a variation of the detail of figures 4 and 5; figure 8 is a partially sectional orthographic projection view of a connector assembly according to the invention in a second embodiment; figure 9 is another orthographic projection view of the assembly of figure 8; figures 10 and 11 are partially sectional orthographic projection views of the connector assembly in a third embodiment. With particular reference to figures 1 to 5, a connector assembly, particularly for the windings of a stator of an electric motor, according to the invention, is generally designated by the reference numeral 10 in a first embodiment. The connector assembly 10 is indeed applied to the stator 11 of an electric motor 12, which is partially shown in the figures. The connector assembly 10, in this embodiment, comprises a connector element 13 which is constituted by a portion 14 for anchoring to the electric motor 12 and by a portion 15 for connection to the stator windings; said portions are mutually monolithic and lie on perpendicular planes. In the connection portion 15, in this case, there are provided seven cavities 16 which are adapted to accommodate terminals, each designated by the reference numeral 17, adapted to provide electrical connection between the stator 11 and the power supply, not shown. Each one of the terminals 17 is constituted by a laminar body 18 which is made of conducting material and comprises two sections which lie on mutually perpendicular planes. A first section 19 is shaped so as to form a flap 20, whose free end is in turn shaped so as to form two mutually opposite wings 21 which are substantially rigid and form a slot 22 in which two elastic tabs 23 converge towards the bottom; said tabs are connected in an L-shaped configuration to a corresponding wing 21. Between the tabs 23, part of the edges of which is sharp, it is possible to insert up to the free ends an electric conductor 24 with an insulating sheath (constituted, in this case, by one of the leads of the stator windings). A second section 25 is shaped so as to form a male element 26 of an electrical connection to a corresponding female terminal 27. In particular, the body 18 is shaped so as to form stroke limiting raised portions 28 at the edges that face the tabs 23. The body 18 is shaped so as to form extraction-preventing tabs 29 which are arranged in pairs on the sides of the first section 19. The second section 25 is instead shaped so as to form the flared free end, and a through hole 30 is formed therein. The terminals 17 are formed as a whole by blanking and plastic deformation from a metal strip. In this embodiment, the cavities 16 of the connector element 13 are shaped in particular so as to form pairs of prism-like seats 31. In particular, for each pair of prism-like seats 31, one of the seats normally accommodates the first section 19 of a corresponding terminal 17, whilst the other seat 31 is used to provide any electrical bridges. The connector element 13 is shaped, at the connection portion, so as to form a cavity 32 onto which the cavities 16 open and in which the second sections 25 of the terminals 17 are placed; said cavity is adapted to form a guided insertion seat for a complementary part, which is connected to the power supply and in this case is constituted by a connector cover 33 which is shaped like a partial box and is inserted in said seat. The connector cover 33 is shaped so as to form a plurality of slots 34 inside which the female terminals 27, connected to cables 35 that arrive from the power supply, can be accommodated. In this case, the cavities 16 continue so as to form slots 16 in which the leads 37 of the stator windings can be inserted. The leads 37 are guided in their connection by a rack 38 formed at the anchoring section 14. In particular, the anchoring portion 14 comprises two arms 39 which are provided, at their free ends, with anchoring teeth 40 and between which there is provided a base 41 with stroke limiting lugs 42. In particular, in this case there are three stroke limiting lugs 42: a central one and two lateral ones. The connector element 13 is particularly adapted to anchor to the frame, designated by the reference numeral 43, of the electric motor 12. With particular reference to figures 8 and 9, a connector assembly, in a second embodiment which exits at right angles to the axis of the motor, is generally designated by the reference numeral 100. In particular, the connector assembly 100 is applied to the stator windings 101 of an electric motor 102 which is shown partially in the figures. The connector assembly 100 comprises a connector element 103, which is constituted by a portion 104 for anchoring to the stator windings 101 and by a portion 105 for electrical connection to said stator windings; said portions are mutually monolithic and lie substantially on a same plane. The connection portion 105 is shaped so as to form, in this case, seven cavities 106 adapted to accommodate terminals 107 which are in turn adapted to provide the electrical connection between the stator and the power supply. In particular, the terminals 107 are fully identical to the terminals 17, to which reference is made for a more detailed description. The connection portion 105, in this case, is continued so as to form a cavity 108 onto which the cavities 106 open; said cavity 108 is adapted to form a seat for the guided insertion of a complementary part, which is connected to the power supply and in this case is constituted by a connector cover 109, in which female terminals 110, to be connected to the corresponding terminals 107, can be accommodated. In particular, the connector cover 109 is shaped so as to form cavities 111 wherein it is indeed possible to accommodate said female terminals 110. Each one of the cavities 108 is also continued so as to form slots 112 wherein it is possible to conveniently insert the leads of the stator windings 101. In this second embodiment, the anchoring portion 104 is shaped so as to form three arms: two lateral ones 113 and a central one 114. The lateral arms 113 have anchoring teeth 115 and the central arm 114 is provided with mutually opposite anchoring teeth 116. The anchoring portion 104 is shaped so as to form two wings 117 which rest against the stator windings 101 and two studs 118 for preventing overturning. With particular reference to figures 10 and 11, a connector assembly, in a third embodiment exiting at right angles to the axis of the motor, is generally designated by the reference numeral 200. In particular, the connector assembly 200 is applied to the frame 201 and to the stator pack 201a of an electric motor 202 which is shown partially in the figures. The connector assembly 200 comprises an element 203, which is constituted by a portion 204 for anchoring to the frame 201 and to the stator pack 201a and by a portion 205 for electrical connection to the stator windings 202a; said portions are mutually monolithic and lie substantially on mutually perpendicular planes. The connection portion 205 is shaped so as to form, in this case, twelve cavities 206 adapted to accommodate terminals 207 which are in turn adapted to provide the electrical connection between the stator and the power supply. In particular, the terminals 207 are fully similar to the terminals 17, to which reference is made for a more detailed description. The connection portion 205, in this case, is continued so as to form a cavity 208 onto which the cavities 206 open; said cavity 208 is adapted to form a seat for the guided insertion of a complementary part which is connected to the power supply and in this case is constituted by a connector cover 209 which can accommodate female terminals 210 to be connected to the corresponding terminals 207. In particular, the connector cover 209 is shaped so as to form cavities 211, inside which said female terminals 210 can be accommodated, and elastic couplings 209a for anchoring to the section 205. Each one of the cavities 208 is continued so as to form slots 212 wherein it is conveniently possible to insert the leads 212a of the stator windings 202a. In this second embodiment, the anchoring portion 204 is shaped so as to form two lateral slots 213 which have a guided coupling, upon assembly, with the edges of a seat 214 for the connector element 203, which is formed in the frame 201. The anchoring portion 204 is continued so as to form a base 215 which lies at right angles to the connection portion 205 and has, at its free end, two pins 216 which are inserted, upon assembly, in corresponding holes 217, formed in the stator pack 201a, so as to guide the anchoring of the connector element 203. The connector assembly 200 also comprises, in this case, a conventional thermal protection element designated by the reference numeral 218. With particular reference to figures 6 and 7, a variation of the terminals 17 or 107 or 207 can conveniently be applied as an alternative both to the assembly 10 and to the assemblies 100 and 200. More specifically, in the variation of the terminal, generally designated by the reference numeral 300, the terminal is constituted by a laminar body 301 made of conducting material, which comprises two sections which lie on mutually perpendicular planes: a first section 302 is shaped so as to form two mutually facing, parallel and identical flaps 303. The free end of each flap 303 is in turn shaped so as to form two mutually opposite substantially rigid wings 304 which form a slot 305 wherein two elastic tabs 306 converge towards the bottom and join in an L-shaped arrangement a corresponding wing 304; an electric conductor with an insulating sheath, not shown, can be inserted up to its free ends between said two tabs, part of whose edges is sharp. A second section 307 is shaped so as to form a male element 308 of an electrical connection with a corresponding female terminal of the previously described type. In particular, the terminal 300 is more rigid than the male elements, with respect to the terminals of which it is a variation, during connection. In practice, it has been observed that the present invention has solved the intended aim and objects. In particular, it should be noted that the execution of a particular configuration of the terminals and of the connector elements allows very easy provision of the electrical connection between the stator windings and the power supply thereof. It should also be noted that electrical connection by means of a connector assembly according to the present invention can occur without the aid of specialized personnel, since it is particularly simple and partly guided by the very structure of the elements that compose said connector assembly. The overall structural flexibility of the connector assembly according to the invention should also be noted. The suitability for mass manufacture of all the components that constitute the connector assembly according to the invention should also be noted. The extreme operating safety achieved by the connector assembly according to the invention should also be noted. The materials and the dimensions may be any according to requirements. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims: A connector assembly for the windings (101, 202a) of a stator (11) of an electric motor (12, 102, 202), comprising a connector element (13, 103, 203) constituted by a portion (14, 104, 204) for anchoring to the electric motor and by a portion (15, 105, 205) for the guided and predefined connection of the stator windings (101, 202a) to a complementary part connected to the power supply, said portions being mutually monolithic, the latter portion having one or more cavities (16, 106, 206) adapted to accommodate terminals (17, 107, 207, 300) for electrical connection between the stator (11) and the power supply, each one of said terminals (17, 107, 207) being constituted by a laminar body (18, 301), made of conducting material, which comprises two sections, a first one (19, 302) of said sections being shaped so as to form at least one flap (20, 303), the free end of said flap being in turn shaped so as to form two substantially rigid mutually opposite wings (21, 304) which form a slot (22, 305) in which two elastic tabs (23, 306) converge towards the bottom, said tabs being connected in an L-shaped configuration to a corresponding wing (21, 304) of said mutually opposite wings, an electric conductor (24) with insulating sheath being insertable up to the free ends between said elastic tabs (23, 306), part of the edges of which is sharp, a second one of said sections (25, 307) being shaped so as to form the male element (26, 308) of an electrical connection to a corresponding female terminal (27, 110, 210), characterized in that the two sections lie on mutually perpendicular planes and each of said wings (19) is shaped so as to form stroke limiting raised portions (28) at the edge that faces said tabs (23). The connector assembly according to claim 1, characterized in that said first section (19, 302) comprises two mutually facing and parallel flaps (20, 303). The connector assembly according to one or more of the preceding claims, characterized in that said first section (19) is shaped so as to form extraction-preventing tabs (29) for preventing extraction of said terminals (17). The connector assembly according to one or more of the preceding claims, characterized in that said terminals (17, 107, 207, 300) are obtained by blanking and plastic deformation starting from a metal strip. The connector assembly according to one or more of the preceding claims, characterized in that said anchoring portion (14, 104) and said connection portion (15, 105) lie on the same plane. The connector assembly according to claim 1, characterized in that said anchoring portion (204) and said connection portion (205) lie on perpendicular planes. The connector assembly according to one or more of the preceding claims, characterized in that said one or more cavities (16) are shaped so as to accommodate, in corresponding single or double prism-shaped seats (31), said first (19) sections of said terminals (17). The connector assembly according to one or more of the preceding claims, characterized in that said connector element (13, 103, 203) can be associated with a complementary part which is connected to the power supply and is constituted by a connector cover (33, 109, 209) which is at least partially box-shaped and inside which one or more female terminals (27, 110, 210) are accommodated, upon assembly, for said second sections (25, 307) of said one or more terminals (17, 107, 207, 300) accommodated in said connector (13, 103, 203).

Inventors: BOISCHIO IDO, BOISCHIO, IDO
Applicants: INARCA SPA, INARCA S.P.A.
Application year: 1997
Main classification: H02K5
IPC codes: H01R4, H02K5, H01R24, H02K3