GB2225489A

GB2225489A - Electrical connection arrangements in a brush-holder for dc electrical machine of a radiator cooling electric fan

Info

Publication number: GB2225489A
Application number: GB8924584A
Authority: GB
Inventors: Walter Zanchi
Original assignee: Industrie Magneti Marelli SRL; Magneti Marelli SpA
Current assignee: Industrie Magneti Marelli SRL; Marelli Europe SpA
Priority date: 1988-11-04
Filing date: 1989-11-01
Publication date: 1990-05-30
Anticipated expiration: 2009-11-01
Also published as: FR2644636B1; ES2017205A6; SE8903682L; SE8903682D0; GB8924584D0; IT8853508V0; BR8905695A; DE3936672A1; TR25467A; IT214920Z2; FR2644636A1; GB2225489B

Description

1 A BRUSH-HOLDER FOR DIRECT-CURRENT ELECTRICAL Ek'1CHINE,2225489

PARTICULARLY FOR THE MOTOR OF AN ELLWRIC FAN FOR COOLING THE RADIATOR OF AN INTERNAL COMBUSTION ENGINE The present invention relates to a brush-holder for a directcurrent electrical machine, particularly for the motor of an electric fan for cooling the radiator of an internal combustion engine.

More specifically, the invention relates to a brush-holder of the type comprising:

- an annular support plate carrying at least one first guide element and one second guide element for a positive brush and for a negative brush respectively, - first and second conductor elements mounted on the plate and having respective ends connected to the brushes, - an electrical interconnection _devic_iefor enabling the conductor elements and hence the brushes to be connected to an external electrical circuit.

The object of the present invention is to provide a brush-holder of the type defined above which is composed of a limited number of parts which can be assembled quickly and easily.

According to the present invention, this object is achieved by virtue of the fact that the electrical interconnection device comprises a shaped support base of electrically insulating material which is snap-engaged in a seat formed in the support plate, first and second connection members of conductive material being mounted in respective separate housings defined in the base and each having:

- a first portion to which one end of one of the conductor elements is connected, and - a substantial ly- flat second portion to which one or more conductors for connection to the external circuit can be soldered.

2 The invention will now be described in detail with reference to the appended drawings, provided purely by way of non-limiting example, in which:

Figure 1 is a plan view of a brush-holder according to the present invention, to which electrical supply conductors are connected, 1 Figure 2 is an exploded perspective view of part of a direct-current motor provided with a brush-holder according to the invention, Figure 3 is a perspective view of the brush-holder of Figure 1, on an enlarged scale, Figure 4 shows brush-holder, a variant of an element of the Figure 5 is an exploded perspective view of part of the brush-holder, Figure 6 is a section taken on the line VI-VI of Figure Figure 7 is a section taken on the line VII-VII of Figure 5, and Figure 8 is a section taken on the line VIII-MI of Figure 7.

In the drawings, a brush-holder for a starter motor for motor vehicles is indicated 1. The brush-holder 1 comprises a plastics support plate 2 with a central hole 3 in which a conventional bladed commutator 4, shown in broken outline in Figure 1, is situated. Four hollow guide elements 5 are fixed on the support plate 2, a brush 6 being slidably mounted in each guide element and being urged against the surface of the 1 3 commutator 4 by a spring (not shown in the drawings). Two shaped copper rods 7 are disposed on the support plate 2 and each electrically connects two diametrallyopposed brushes 6. Each brush 6 is connected to a rod 7 by means of a copper braid 8 having one end fixed to the rear part of the brush 6 and the other end clamped to the rod 7. Each rod 7 has one end, indicated 9 in the drawings, which is connected to a respective plate 10 of a conductive material.

As can be seen in Figures 2 and 3, each plate 10 has a first portion 11 which faces inwardly of the support plate 2 and has the end 9 of a respective rod 7 soldered to its upper surface. Each plate 10 also has a second flat portion 12 whose side edges 13 are bent downwards. The ends of a plurality of conductors 14 are soldered to the lower part of the portion 12 of each plate 10. In the embodiment illustrated in the drawings, one of the two plates 10 is wider than the other and the ends of three conductors 14 are connected thereto, whilst the ends of two conductors 14 are fixed to the narrower plate 10.

Alternatively, according to a variant shown in Figure 4, the first portion 11 of each plate 10 has an appendage lla which is bent to form a clip for the clamping (and possible soldering) of the end 9 of the respective rod 7 and one end of a braid 8.

With reference now to Figures 2 and 3, the two plates 10 are arranged in respective housings 15 formed in a support base 16 of moulded plastics material, visible in greater detail in Figure 5. The base 16 has a bottom wall 17 from which rise two side walls 18 and an intermediate wall 19 for separating the two housings 4 15. The plates 10 are inserted in the housings 15 of the support base 16 in the direction indicated by the arrow A in Figure 2 and their bent side edges 13 bear on the bottom wall 17 of the base 16. The base 16 has stop projections 20 and 21 against which the end portions of the bent edges 13 and the upper surfaces 12 of the plates 10 bear respectively.

The support base 16 is inserted in a seat 22 formed in the support plate 2. Each side wall 18 of the support base 16 has a retaining tab 23 on its side facing outwardly of the base, for engaging in a corresponding recess 24 formed in the seat 22 of the support plate 2.

As shown in Figure 2, the brush-holder 1 is mounted at one end of the tubular casing 25 of the electric motor and that end is then closed by a metal base 26. One of the end edges of the casing 25 has two recesses 27 in which respective protuberances projecting radially from the support plate 2 are positioned. The conductors 14, whose ends are fixed to the plate 10, emerge from the casing 25 through an aperture 29 formed in the side wall thereof. The aperture 29 of the casing 25 is closed by a sealing element 30 of resiliently deformable material, for example rubber. The sides of the sealing element 30 which correspond to the edges of the aperture 29 have channel-shaped end portions 31 so as to fit sealingly on to the edges of the aperture. The edge of the sealing element 30 which faces the brush-holder 1, indicated 32, has a plurality of notches 33 which extend from the edge to a plurality of apertures 34 provided for the passage of the conductors 14. These notches enable the easy insertion of the conductors 14 in the apertures 34 of the element 30.

On its side which faces away from the support plate 2, the support base 16 has an arcuate portion 35 which is recessed from the plane of the bottom wall 17 and has a channel-shaped section for sealingly housing the edge 32 of the element 30.

6

Claims

1. A brush-holder for a direct-current electrical machine, particularly for the motor of an electrical fan for cooling the radiator of an internal combustion engine, comprising:

- an annular support plate carrying at least one first guide element and one second guide element for a positive brush and-for a negative brush respectively, - first and second conductor elements mounted on the plate and having respective ends connected to the brushes 01 - an electrical interconnection device for enabling the conductor elements and hence the brushes to be connected to an external electrical circuit, characterised in. that the electrical interconnection device comprises a shaped support base of electrically insulating material which is formed in the support plate, first and second connection members of conductive material being mounted in respective separate housings each having:

snap-engaged in a seat defined in the base, and a first portion to which one end (9) of one of the conductor elements is connected, and a substantially flat second portion to which one or more conductors for connection to the external circuit can be soldered.

2. A brush-holder according to Claim 1, characterised in that the conductor elements are each soldered to one of the connection members.

3. A brush-holder according to Claim 1, characterised in that the conductor elements are each connected 7 to one of the connection members possibly soldering.

by clamping and

4. A brush-holder according to any one of the preceding claims, characterised in that the support base is of moulded plastics material.

5. A brush-holder according to any one of the preceding claims, characterised in that the connection members of the interconnection device are made of copper or an alloy thereof.

6. A direct-current electrical machine, particularly for the motor of an electric fan for cooling the radiator of an internal combustion engine for motor vehicles, characterised in that it includes a brush-holder according to one or more of the preceding claims.

7. An electrical machine according to Claim 6, including a cylindrical casing to the ends of which closure bases are coupled, and in which an aperture for the passage of the conductors for connecting the brushes to an external circuit is defined, characterised in that a sealing closure element of electrically-insulating material is coupled to the aperture and has apertures through each of which one of the connecting conductors extends.

8. An electrical machine according to Claim 7, characterised in that the aperture in the cylindrical casing is constituted by an end notch of the casing, the radially outermost portion Of the base of the brush-holder having an arcuate 8 groove which lies on a circumference coaxiaL with the brush-holder and is adapted axially to house an end edge of the sealing closure element.

9. An electrical machine according to Claim characterised in that the sealing closure element has a plurality of notches each of which extends from the end edge to a corresponding aperture in the closure element so as to enable one of the conductors to be positioned in the aperture,,

10. A brush holder for a direct-current electrical machine substantially as hereinbefore described with reference to the accompanying drawings.

Published 1990 at The Patent Office. State House. 66 71 High Holborn. LondonWClR4TF. Further copies maybe obtained from The Patent Off'CC Sales Branch. St. Mary Cray. Orpington. Kent ER5 3RD Printed by Multiplex techniques ltd- St Mary Crky. Kent. Con 1 87