Electromagnetic device

• US 20020050751A1
• Filed: 09/24/2001
• Published: 05/02/2002
• Est. Priority Date: 10/30/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hashimoto, Naoya, Ohta, Hirohisa, Ozawa, Hiromasa, Sugano, Chiaki, Hasegawa, Shiro, Miyaoku, Teruo
• Granted Patent: US 6,927,507 B2
• Time in Patent Office: Days
• US Class Current: 310/71
• CPC Class Codes: F16H 61/32 Electric motors actuators or related electrical control means therefor
• CPC Class Codes: H02K 3/44 Protection against moisture or chemical attack; Windings specially adapted for operation in liquid or gas
• CPC Class Codes: H02K 3/525 Annular coils, e.g. for cores of the claw-pole type
• CPC Class Codes: H02K 5/225 Terminal boxes or connection arrangements specially adapted for submersible motors H02K5/132

Abstract

A stepping motor being a motor used in oil includes a coil formed with a conductor coated with an outer coating and wound around a bobbin, and coil terminals electrically connected to the conductor at ends thereof led out from the coil, the outer coating being removed from the conductor at the ends thereof. The coil terminals are coated with a protective film made of a material having low permeability to elemental sulfur and sulfur compounds. Therefore, coil terminals and ends of the conductor are prevented from erosion by sulfur and organic sulfur compounds, thereby reducing risk of disconnection in the coil terminals and the conductor.

Claims

1. An electromagnetic device used in oil, comprising:

a coil including a conductor coated with an outer coating and wound around a bobbin; and

a coil terminal electrically connected to said conductor at an end part thereof which is led out from said coil, the outer coating at said end part of said conductor being removed,

at least one of said coil terminal and said end part is coated with a protective film, respectively, made of a material having low permeability to elemental sulfur and sulfur compounds.

3. An electromagnetic device according to claim 1, wherein said protective film is coated with a overcoat made of a resin having low permeability to elemental sulfur and sulfur compounds.

4. An electromagnetic device according to claim 1, wherein said protective film is composed of a high-temperature solder.

2. An electromagnetic device used in oil, comprising:

a coil including a conductor coated with an outer coating and wound around a bobbin; and

a coil terminal electrically connected to said conductor at an end part thereof which is led out from said coil, the outer coating at said end part of said conductor being removed,

wherein at least one of said coil terminal and said end part is coated with an overcoat made of a resin having low permeability to elemental sulfur and sulfur compounds.

5. An electromagnetic device according to claim 2, wherein said overcoat comprises a thermoset epoxy resin.

6. An electromagnetic device according to claim 2, wherein said overcoat comprises a thermoset modified-phenol resin.