GB2074264A

GB2074264A - Twin disc brake

Info

Publication number: GB2074264A
Application number: GB8111948A
Authority: GB
Original assignee: Valeo SE
Current assignee: Valeo SE
Priority date: 1980-04-18
Filing date: 1981-04-15
Publication date: 1981-10-28
Also published as: ES8203134A1; ES501417A0; IT8112507A0; FR2480881B1; IT1147152B; DE3115260A1; FR2480881A1; GB2074264B

Abstract

A brake includes a rotary member to be braked comprising two spaced ventilated discs (10) each carried by a respective hub element (11), the elements being connected to radially extending support means (12) and each hub element being provided, at circumferentially spaced locations, with ventilation apertures (17). The two hub elements (11) are encircled by a unitary collar member (20) disposed adjacent the outer surfaces of the hub elements (11). The collar member (20) has openings (21) positioned opposite the ventilation apertures (17) in the hub elements. Such a brake is particularly suitable for use in heavy automobile vehicles. <IMAGE>

Description

SPECIFICATION Twin-disc brake The present invention relates generally to twindisc brakes, that is to say brakes having a rotary member to be braked comprising two spaced, substantially parallel annular discs.

Twin-disc brakes of this kind can, for example, be used in heavy automobile vehicles, as mentioned in particular in the French patent filed on 13th June, 1 975 under Application No.

75 18525 and published under No.2,314,399.

In practice, the two discs are each carried by a respective axially extending hub element, these elements being connected to radially extending support means, while the support means may be disposed back to back and both fastened by screws, in this back-to-back position, to a flange fastened to the shaft of a wheel to be braked.

One of the problems to be solved in theconstruction of twin-disc brakes of thins kind is to ensure suitable ventilation of the space within the hub elements.

In French Patent No. 1,519,112, which relates to a single-disc brake, it has been proposed to provide perforations in the hub carrying the disc.

However, in this French patent the perforations extend circumferentially, and their axial dimension is only a fraction of the axial extent of the hub.

Although this arrangement may be satisfactory for a single-disc brake, it is not so for a twin-disc brake, for which ventilation provided in this manner is found, in practice, to be insufficient.

In addition, in this French Patent No.

1,519,112, the perforations extend a considerable distance into the web which connects the disc to the hub, However, since this is a zone subject to heavy thermal stresses, any weakening is not an advantage.

It is an object of the present invention to provide a twin-disc brake in which it is possible to provide suitable ventilation of the brake without weakening the webs connecting the discs to their respective hubs.

According to the invention there is provided a brake comprising a rotary member to be braked having two spaced, substantially parallel annular discs, each disc being carried by a respective axially extending hub element, the elements being connected to radially extending support means, each hub element being provided, at circumferentially spaced locations, with ventilation apertures, and both hub elements being encircled by a unitary collar member, disposed adjacent the outer surfaces of the hub elements, which collar member has openirigs positioned opposite the ventilation apertures in the hub elements.

Good ventilation and good mechanical strength of the brake are thus both ensured.

It is preferable for one of the axially extending edges of each of the openings in the collar member to be formed with a tongue, at least a portion of which extends radially into a space defined by the hub elements through respective ventilation apertures in the hub elements, said tongue portion comprising a paddle in the space within the hub elements.

Agitation of the air in this space is thus improved.

Embodiments of the invention will now be described, by way of example only and with reference to the accompanying schematic drawings, in which: Figure lisa partial view in axial section of the rotary member of a twin-disc brake according to the invention, taken on the line I-I in Figure 2; Figure 2 is a view in elevation, partly broken away, of the rotary member of Figure 1 viewed in the direction of the arrow II in Figure 1; and Figure 3 is a partial view of the rotary member in transverse cross section on the line Ill-Ill in Figure 1; Figure 1 shows the rotary member of a twindisc brake.

The rotary member comprises two spaced annular discs 10, which are disposed substantially parallel to one another, and which are each carried by a respective axially extending hub element 11, which elements are each connected to radially extending support means 12.

In the embodiment illustrated, the discs 10 are of the ventilated type and each of them is connected to the corresponding hub elements 11, by means of a web 14, at that end of the hub element axially opposite that at which the hub element is connected to the corresponding support means 12.

In addition, in the embodiment illustrated, the two support means 12 are disposed back to back and, as shown in broken lines, they are intended to be both attached, in this back-to-back position, by means of screws 1 5 to a flange 1 6 fastened to the shaft of a wheel to be braked.

Each hub element 11 is provided, at circumferentially spaced intervals, with ventilation apertures 1 7 which extend axially over at least a portion of the axial extent of the hub element.

In practice, the ventilation apertures 1 7 of one hub element are disposed axially opposite those in the other hub element 11.

Moreover, in the embodiment illustrated, the ventilation apertures 17 in each hub element 11 are disposed opposite the support means 12, with the result that in this embodiment, each ventilation aperture 1 7 of one hub element communicates with a respective aperture 1 7 in the other hub element 11, so that the apertures of each pair axially extend continuously from one hub element 11 to the other, to form an axially elongated opening 1 8.

In the embodiment illustrated the ventilation apertures 1 7 of each hub element 11 terminate some distance from the corresponding web 1 4.

The two hub elements 11 are encircled by a unitary collar member 20, which has axially elongated openings 21 disposed opposite the ventilation apertures 1 7 in the hub elements 11.

One of the axially extending edges of each of the openings 21 is formed with a tongue 22, which, in the embodiment illustrated, extends radially into the space within the hub elements 11, through the corresponding ventilation apertures 1 7 in the latter. Each tongue 22 is formed with a bend 23 and comprises a paddle 24 which extends beyond the bend and which is directed generally circumferentially; in practice, and as illustrated, the tongues 22 are integral with the collar member 20, originating from respective openings 21 in the collar member.

In the embodiment illustrated, each tongue 22 is provided in its axial middle region with.a cutout 25 for engagement of the tongue 22 on the support means 12 of the hub elements 11.

The collar member 20 may, for example, be placed in position on the hub elements 11 by axial engagement of the two hub elements 11 taking place within the collar member 20 itself, each hub element being disposed at a respective axial end of the collar member. In such a case, the collar member 20 may be of ready closed configuration, but its tongues 22 must not be folded inwards until after axial engagement of the hub elements 1 The tongues 22, which are previously suitably shaped, are then folded to extend through both the openings 21 in the collar member 20 and through the ventilation apertures 1 7 in the hub elements 1 1.

In an alternative embodiment, the collar member 20 may be placed in position by closing it around the hub elements 11, with simultaneous engagement of its tongues 22 in the ventilation apertures 1 7 in the hub elements. It may instead be composed of two half-collar members suitably mutually disposed and interconnected.

The present invention is moreover not limited to the embodiments described and illustrated, but includes any variant of construction and/or combination.

In particular, at least a portion of the tongues with which the collar member is preferably provided, may project inwardly, for example radially, as shown in broken lines in Figure 3 for one of the tongues, or instead each tongue may have a portion directed inwardly and a portion directed outwardly. In addition, these different arrangements may be combined.

Furthermore, the ventilation apertures in the hub elements are not necessarily disposed opposite the support means for the hub elements, and in this case, these tongues are then divided into two half-tongues, one for each hub element, the central cutout in the tongues being enlarged sufficiently.

Claims

1. A brake comprising a rotary member to be braked having two spaced, substantially parallel annular discs, each disc being carried by a respective axially extending hub element, the elements being connected to radially extending support means, each hub element being provided, at circumferentially spaced locations, with ventilation apertures, and both hub elements being encircled by a unitary collar member, disposed adjacent the outer surfaces of the hub elements, which collar member has openings positioned opposite the ventilation apertures in the hub elements.

2. A brake according to Claim 1. in which one axially extending edge of each opening in the collar member is formed with a tongue.

3. A brake according to Claim 2, in which at -least a portion of each said tongue extends radially into a space defined by the hub elements through respective ventilation apertures in the hub elements and comprises a paddle in the space within the hub elements.

4. A brake according to Claim 3, in which each said tongue has a cutout in its axial middle region for engagement on the support means for the hub elements.

5. A brake according to any of Claims 2 to 4, in which at least a portion of each said tongue projects inwardly.

6. A brake substantially as hereinbefore described, with reference to the accompanying drawings.