Electric motor assembly device

Abstract

An electric motor assembly device includes a carrier member with a central passage that receives a rotor shaft with a commutator. Brushes secured onto flexible, brush holders urge the brushes towards the central passage into a contact position with the commutator. The carrier member has mechanical elements for restraining the brush holders in an assembly position for assembly where the brushes clear the central passage and are protected against impact by the carrier member. This arrangement allows the rotor shaft to be introduced into the central passage of the carrier member without a risk of damaging the brushes. The brush holders are easily released automatically from the mechanical elements on the electric motor assembly device to bring the brushes into the contact position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a, which has already been described, is a diagrammatic view of a commutator housing according to the prior art with brushes in an assembly position;

FIG. 1 b, already described, shows a prior art commutator housing with the brushes in a contact position;

FIG. 2 is a diagrammatic exploded view of an assembly device according to the invention;

FIG. 3 is a diagrammatic view of the assembly device of FIG. 2 once assembled, with brushes in the contact position;

FIG. 4 shows the assembly device of FIG. 2 assembled with the brushes in the assembly position, and with a printed circuit board; and

FIG. 5 is an exploded view of an electric motor including the assembly device according to the invention.

Claims

1. An electric motor assembly device comprising: a carrier member having a substantially cylindrical central passage adapted to receive a rotor shaft provided with a commutator; andbrushes that are each secured onto a flexible brush holder that urges the brushes towards the substantially cylindrical central passage and into a position of contact with the commutator,wherein the carrier member includes mechanical elements for retaining the flexible brush holders in an assembly position outside of the substantially cylindrical central passage, and the brushes are protected by the carrier member when in the assembly position.

2. The assembly device according to claim 1, further including a partly-spherical bearing member for guiding the rotor shaft, wherein the carrier member includes a mechanical feature for retaining the partly-spherical bearing member.

3. The assembly device according to claim 2, wherein the mechanical feature is constituted by a reduced diameter portion of the substantially cylindrical central passage in the carrier member.

4. The assembly device according to claim 1, further including a printed circuit board secured to the carrier member wherein the flexible brush holders are connected to the printed circuit board.

5. The assembly device according to claim 4, wherein the flexible brush holders are adapted to electrically supply the brushes.

6. The device according to claim, wherein the printed circuit board includes an insulating support that is of a one-piece construction with the carrier member.

7. The assembly device according to claim 1, wherein the mechanical elements for retaining the flexible brush holders in the assembly position are stem or finger members which extend substantially parallel to an axis of the substantially cylindrical central passage in the carrier member.

8. The assembly device according to claim 7 wherein the stem or finger members are flexible in a direction substantially parallel to the flexible brush holders.

9. A direct current electric motor comprising an assembly device including a carrier member having a substantially cylindrical central passage adapted to receive a rotor shaft provided with a commutator, and brushes that are each secured onto a flexible brush holder member that urges the brushes towards the substantially cylindrical central passage and into a position of contact with the commutator, wherein the carrier member includes mechanical elements for retaining the flexible brush holders in an assembly position outside of the substantially cylindrical central passage, and the brushes are protected by the carrier member when in they assembly positionthe rotor shaft extending in the substantially cylindrical central passage; andan outer casing including shapings for releasing the mechanical elements.

10. A method for mounting a rotor shaft in a casing of an electric motor, the method comprising the steps of: supplying an assembly device including a carrier member having a substantially cylindrical central passage adapted to receive a rotor shaft provided with a commutator, and brushes that are each secured onto a flexible brush holder that urges the brushes towards the substantially cylindrical central passage and into a position of contact with the commutator, wherein the carrier member includes mechanical elements for retaining the flexible brush holders in an assembly position outside of the substantially cylindrical central passage, the brushes are protected by the carrier member when in the assembly position and the flexible brush holders are maintained outside the substantially cylindrical central passage;introducing the rotor shaft provided with the commutator into the substantially cylindrical central passage, wherein the brushes are protected by the carrier member; andplacing the assembly device along with the rotor shaft into an outer casing that includes shapings adapted to actuate the mechanical elements to release the flexible brush holders from the assembly position.