Electric motor

• US 20020067094A1
• Filed: 06/05/2001
• Published: 06/06/2002
• Est. Priority Date: 12/05/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hashimoto, Akira, Sugiyama, Takeshi, Nakahara, Yuji, Yagyu, Yasuhide, Okazaki, Masafumi, Megata, Hideki
• Granted Patent: US 6,600,244 B2
• Time in Patent Office: Days
• US Class Current: 310/180
• CPC Class Codes: H02K 2203/09 Machines characterised by wiring elements other than wires, e.g. bus rings, for connecting the winding terminations
• CPC Class Codes: H02K 3/522 for generally annular cores with salient poles

Abstract

The invention provides a small-sized and inexpensive electric motor in which connection of a stator coil is easily and connecting portion occupies a small space. Stable torque characteristic is obtained by making electric resistance values uniform.

A coil bobbin 4 is mounted on a magnetic pole 3b of a stator core 3, and a stator coil 5 is fitted. A lead wire 5a is led to an external diameter side of one end of the stator core 3. A connecting conductor holder 10, in which a common coil-connecting conductor 6a and connecting conductors 7a, 8a and 9a for each phase are accommodated and a through hole 10f opened, is mounted on an end of a coil bobbin 4. The common coil-connecting conductor 6a has connecting terminals 6b, 7b, 8b and 9b projecting in radial direction, and the connecting conductors 7a, 8a and 9a for each phase have such a cross-sectional area as to equalize electric resistance of each phase after connecting the stator coil 5. Thus a space 17 is formed to allow a bearing-housing portion 12a to be inserted, and a connecting portion 11 is formed by connecting each of the connecting terminals 6b, 7b, 8b and 9b with lead wire 5a on the external diameter side of the connecting conductor holder 10.

Claims

1. A electric motor comprising:

a plurality of stator coils wound around a magnetic pole of a stator core, and of which lead wires are led to an external diameter side in the vicinity of one end of the stator core;

a connecting conductor holder being an insulating annular member having a through hole at the central part, in which a plurality of accommodating grooves opened to one side and formed in belt shape in circumferential direction are provided in diameter direction so as to be located in close proximity to the lead wires of said stator coils;

first and second connecting conductors having a belt-like conductor accommodated in said accommodating grooves of said connecting conductor holder, and connecting terminals provided projecting from the mentioned belt-like conductor to the external diameter side of said connecting conductor holder and each connected to a predetermined lead wire of said stator coils;

wherein the lead wires of said stator coils of same phase are connected to each other through said first connecting conductor, and the lead wires to be connected to an electrically neutral point of said stator coils are connected through said second connecting conductor.

2. The electric motor according to claim 1, wherein the connecting conductor holder has the through hole for forming a space in which a bearing-housing portion is inserted, said bearing-housing portion supporting a bearing of the electric motor arranged in the vicinity of said connecting conductor holder.

3. The electric motor according to claim 1, wherein the first connecting conductor has a sectional area to make electric resistance of each phase equal after connecting the lead wires of said stator coils.

4. The electric motor according to claims 1, wherein the first connecting conductor has an external terminal formed by bending an end part of the belt-like conductor toward a side where the connecting terminal is provided.

5. A electric motor comprising:

a plurality of stator coils wound around a magnetic pole of a stator core, and of which lead wires are led to an external diameter side in the vicinity of one end of the stator core;

a connecting conductor holder being an insulating annular member having a through hole at the central part, in which a plurality of accommodating grooves opened to one side and formed in belt shape in circumferential direction are provided in diameter direction so as to be located in close proximity to the lead wires of said stator coils;

first connecting conductors having a belt-like conductor accommodated in said accommodating grooves of said connecting conductor holder, and connecting terminals provided projecting from the mentioned belt-like conductor to the external diameter side of said connecting conductor holder and each connected to a predetermined lead wire of said stator coils;

second connecting conductor having a conductor plate mounted on a side of the connecting conductor holder located on the opposite side of projecting connecting terminals of the first connecting conductor, and connecting terminals projecting from the conductor plate to the external diameter side of said connecting conductor holder and each connected to a predetermined lead wire of said stator coils;

wherein the lead wires of said stator coils of same phase are connected to each other through said first connecting conductor, and the lead wires to be connected to an electrically neutral point of said stator coils are connected through said second connecting conductor.

6. The electric motor according to claim 5, wherein the second connecting conductor plate is composed of a plurality of connecting conductor plates having conductor plate segments and connecting terminals provided projecting from said conductor plate segment.