WHEEL DRUM BRAKE ASSEMBLY

Abstract

The invention at hand refers to a wheel drum brake assembly comprising a wheel rim and an annular brake ring with intermediate bridges, wherein the wheel rim and the annular brake ring are arranged in a concentric manner and the annular brake ring is connected to the wheel rim by the intermediate bridges such as to let air circulate between the inner surface of the wheel rim and the outer surface of the annular brake ring with a normal vector pointing in a radial direction of the annular brake ring. The wheel drum brake assembly also comprises a drum brake caliper with at least one brake shoe, wherein the caliper and the at least one brake shoe are arranged at the inner circumference of the annular brake ring.

Claims

1. A wheel drum brake assembly comprising a wheel rim and an annular brake ring with intermediate bridges, wherein the wheel rim and the annular brake ring are arranged in a concentric manner and the annular brake ring is connected to the wheel rim by the intermediate bridges and said intermediate bridges are arranged such as to let air circulate between the wheel rim and the outer surface of the annular brake ring with a normal vector pointing in a radial direction of the annular brake ring, a drum brake caliper with at least one brake shoe, wherein the caliper and the at least one brake shoe are arranged at the inner circumference of the annular brake ring and the at least one brake shoe is configured to press against the inner surface of the annular brake ring in a radial direction of the annular brake ring during braking.

2. Wheel drum brake assembly according to claim 1, characterized in that a coupler ring is arranged between the wheel rim and the annular brake ring in a concentric manner, wherein the outer surface of the coupler ring with a normal vector pointing in a radial direction of the coupler ring is connected to the inner surface of the wheel rim in a planar manner and the inner surface of the coupler ring is connected to the intermediate bridges.

3. Wheel drum brake assembly according to claim 2, characterized in that the coupler ring is made of a thermally insulating material and/or an elastically deformable material.

4. Wheel drum brake assembly according to claim 2, characterized in that the coupler ring is connected to the wheel rim and/or the intermediate bridges via at least one bolt, press fit, welding or adhesive bonding.

5. Wheel drum brake assembly according to claim 1, characterized in that the annular brake ring is coupled to a spoke detachable from the wheel rim.

6. Wheel drum brake assembly according to claim 1, characterized in that the wheel rim and/or the annular brake ring comprises aluminium and/or cast iron and/or stainless steel.

7. Wheel drum brake assembly according to claim 1, characterized in that a friction material coating is applied to at least a part of the inner surface of the annular brake ring comprising steel, iron, copper, adhesive materials, asbestos materials or non-asbestos organics.

8. Wheel drum brake assembly according to claim 1, characterized in that the radial thickness of the annular brake ring is less than 60 mm and/or the width of the annular brake ring is less than 80 mm.

9. Wheel drum brake assembly according to claim 1, characterized in that the intermediate bridges are an integral part of the annular brake ring and made of the same material as the annular brake ring.

10. Wheel drum brake assembly according to claim 1, characterized in that the intermediate bridges are bolts by which the annular brake ring is fixed to the wheel rim.

11. Wheel drum brake assembly according to claim 1, characterized in that the centroid of the annular brake ring corresponds to the centroid of the wheel rim.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1 shows a schematic side view of the wheel drum brake assembly,

[0031] FIG. 2 shows a schematic cross section of the wheel drum brake assembly along the line A-A in FIG. 1.

DETAILED DESCRIPTIONS

[0032] FIG. 1 shows a schematic side view of a wheel drum brake assembly comprising a wheel rim 1, a coupler ring 5 and an annular brake ring 2 arranged in a concentric manner. Intermediate bridges 3 are an integral part of the annular brake ring 2 and are connected to the inner surface of the coupler ring 5. The intermediate bridges 3 are arranged equidistantly around the circumference of the annular brake ring 2.

[0033] An outer surface of the coupler ring 5 with a normal vector pointing in a radial direction connects to an inner surface of the wheel rim 1 in a planar manner. An outer surface of the annular brake ring 2 with a normal vector pointing in a radial direction is arranged at a distance from the inner surface of the coupler ring 5, wherein the annular brake ring 2 and the coupler ring 5 are connected via intermediate bridges 3 arranged between the inner surface of the coupler ring 5 and the outer surface of the annular brake ring 2 with a normal vector pointing in a radial direction. A drum brake caliper 4 is arranged at the inner circumference of the annular brake ring 2 with maximal distance to ground.

[0034] The wheel rim 1 and the annular brake ring 2 as well as the intermediate bridges 3 are made of aluminium taking advantage of its low mass and high thermal conductivity, which improves heat dissipation and avoids conning and hot spots. The coupler ring 5 is made of an elastic polymer, which provides thermal insulation for the wheel rim 1.

[0035] The wheel rim 1 and the intermediate bridges 3 are connected to the coupler ring 5 via bolts. Alternatively, the intermediate bridges 3 can be realized as bolts directly fixing the annular brake ring 2 to the inner surface of the coupler ring 5. The connection between the coupler ring 5 and the intermediate bridges 3 or between the coupler ring 5 and the wheel rim 1 may alternatively or additionally be realized by a press fit, welding or adhesive bonding.

[0036] The braking surface of the annular brake ring 2, which is a part of the inner surface of the annular brake ring 2, comprises a friction material applied as a coating layer made of a metallic composite with good adhesion to aluminium such as a stainless steel composite.

[0037] In the depicted embodiment, the radial thickness of the coupler ring 5 is between 10 mm and 20 mm. The width of the coupler ring 5 is between 30 mm and 40 mm. The radial thickness of the annular brake ring 2 is between 40 mm and 60 mm. The width of the annular brake ring 2 is between 60 mm and 80 mm. The distance between the inner surface of the coupler ring 5 and the outer surface of the annular brake ring 2 with a normal vector pointing in a radial direction is between 5 mm and 15 mm.

[0038] All three concentric components, i.e., the wheel rim 1, the coupler ring 5 and the annular brake ring 2 are arranged symmetrically and share a common centroid.

[0039] A cross sectional view of the wheel drum brake assembly along line A-A in FIG. 1 is shown in FIG. 2. Recurring features in the figures in each case are denoted with identical reference signs. The caliper 4 comprises a brake shoe arranged inside the caliper housing. The brake shoe is configured to move towards the inner surface of the annular brake ring 2 and press against the annular brake ring 2 for braking.

[0040] FIG. 1 and FIG. 2 depict four pairs of intermediate bridges 3, where each pair of intermediate bridges 3 is arranged on a common line that is parallel to the axis of rotation. It is also possible that more or less pairs of intermediate bridges 3 connect the annular brake ring 2 and the coupler ring 5. In particular, the intermediate bridges 3 can replace the spokes of the wheel such that no separate system of spokes is necessary. Alternatively, the annular brake ring 2 can be coupled to a separate spoke that is detachable from the wheel rim 1.

[0041] Features of the different embodiments which are merely disclosed in the exemplary embodiments as a matter of course can be combined with one another and can also be claimed individually.