Miniature motor

• US 4,853,576 A
• Filed: 04/13/1987
• Issued: 08/01/1989
• Est. Priority Date: 05/01/1986
• Status: Expired due to Term

• Current Assignee: Mabuchi Motor Company Limited
• Original Assignee: Mabuchi Motor Company Limited
• Inventors: Hiromasa, Kunio, Mayumi, Etsuo
• Primary Examiner(s): SKUDY, ROBERT
• Application Number:
  US07/037,737
• Time in Patent Office: 841 Days
• Field of Search: 310/239, 310/242, 310/245, 310/247, 310/246, 310/40 MM, 310/42, 310/88, 310/89, 310/91, 310/71, 310/154, 310/43, 29/597
• US Class Current: 310/239
• CPC Class Codes: H02K 5/145 Fixedly supported brushes or brush holders, e.g. leaf or leaf-mounted brushes
• CPC Class Codes: H02K 5/15 Mounting arrangements for bearing-shields or end plates
• CPC Class Codes: Y10T 29/49011 Commutator or slip ring assembly

Abstract

A miniature motor having a motor case comprising a motor housing, fitted with a permanent magnet field and having an opening at one end thereof; an insulating brush base, made of a synthetic resin, fitted to the opening of the motor housing for holding brushgear; and a cover plate, made of a metallic member, covering the surface of the insulating brush base; the motor housing having a plurality of crimping pieces formed by notching the edge of the motor housing opening; the cover plate being fitted to the motor housing by engaging the cover plate with the motor housing opening, and bending and crimping the crimping pieces, characterized in that the cover plate has along the outer periphery thereof a plurality of recesses, which are concave toward the motor shaft, and the recesses are crimped by means of the crimping pieces so as to fixedly fit the cover plate to the motor housing.

Claims

1. A miniature motor comprising:

a miniature motor housing with a substantially cylindrical housing wall defining a motor chamber, said miniature motor housing having an open end, said miniature motor housing having crimping portions formed in said cylindrical housing wall at spaced locations adjacent said miniature motor housing open end, each of said crimping portions including side portions disconnected from said miniature motor housing and each of said crimping portions including a base portion connected to said miniature motor housing;

a permanent magnet positioned within said motor housing motor chamber;

a cover member for engagement with said miniature motor housing at said miniature motor housing open end, including a substantially annular insulating brush base member formed of synthetic resin having an outer circumferential surface of a predetermined width engaging with the miniature motor housing, said insulating brush base member including means to support a commutator brush, said insulating brush base member including recess portions formed in said outer circumferential surface, said insulating brush base member being positioned in said housing through said housing opening such that said recess portions are in alignment with said crimping portions of said housing; and

, a metallic member cover plate formed of metallic material engaging said miniature motor housing and said brush base insulating member to cover said brush base insulating member and to cover said miniature motor housing open end, said cover plate having a plurality of recesses corresponding in number and position to said brush base member recess portions in alignment with said crimping portions, said brush base insulating member and said cover plate being fixedly fitted to said housing by said crimping portions which extend into respective recesses, said recesses and crimping portions being in crimping engagement.

2. A miniature motor according to claim 1, wherein:

said recess portions of said brush base insulating member include insulating recess portions associated with each of said brush base recess portions for separating and insulating a motor within said motor chamber from exterior of said motor chamber.

3. A miniature motor according to claim 1, wherein:

said insulating brush base member includes terminal mounts defining terminal holes through which brush terminals pass, said cover portion including boss alignment holes adapted to receive crimping portions bosses of said cover plate when said cover plate and said base brush insulating member are in engagement with said housing, said crimping bosses and said boss alignment holes acting to align said cover plate and said base brush insulating member for engagement with said housing.

4. A miniature motor according to claim 1, wherein:

said cover plate recess is defined by a protruding lower portion adapted to engage one of said recess portions of said base brush insulating member.

5. A miniature motor according to claim 1, wherein:

said cover plate recesses are formed by stamping recesses into said cover plate thereby forming a recess on one side of said cover plate and a protruding portion on an opposite side of said cover plate.