Braking band of a disk for disk brake

Patent metadata

Field	Value
Publication number	US-12449011-B2
Application number	US-202017757574-A
Country	US
Kind code	B2
Filing date	Dec 15, 2020
Priority date	Dec 20, 2019
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A braking band having an annular band body arranged around a rotation axis and made of one of gray cast iron, steel, aluminum or alloys thereof, has at least one braking surface having an activated band body portion for increasing adhesive capacity of at least one protective surface coating placed on the surface of the activated band body portion and having at least one material with elevated resistance to abrasion. The activated band body portion is arranged on the surface of the annular band body to form an outermost layer of the braking band with the at least one protective surface coating and has a rough profile having at least one channel delimited by at least one pair of projections, extending along a path at least partially surrounding the rotation axis and having a channel bottom and a first channel side forming an acute angle with the channel bottom and an opposite second channel side forming an obtuse angle with the channel bottom.

First claim

The invention claimed is:

1. A braking band of a disk for a disk brake, said braking band comprising an annular band body arranged around a rotation axis (X-X), said annular band body being made of one of gray cast iron, steel, aluminum or alloys thereof,
said braking band further comprising at least one braking surface,
wherein, at least one portion of said at least one braking surface comprises an activated band body portion for increasing adhesive capacity of at least one protective surface coating placed on a surface of said activated band body portion,
wherein said at least one protective surface coating comprises at least one material with elevated resistance to abrasion,
wherein said activated band body portion is arranged on a surface of said annular band body to form an outermost layer of the braking band with said at least one protective surface coating,
and wherein said activated band body portion comprises a rough profile,
said rough profile comprising at least one channel delimited by at least one pair of projections,
said at least one channel extending along a path that at least partially surrounds said rotation axis (X-X),
and wherein said at least one channel has a channel bottom, and two opposite channel sides in cross section, at a longitudinal extension thereof, namely
a first channel side forming an acute angle with said channel bottom, that is an angle smaller than 90°, and
a second channel side forming an obtuse angle with said channel bottom, that is an angle larger than 90°,
wherein said annular band body is formed by a base metal selected from gray cast iron or steel, wherein:
a protective base coating covers said at least one activated band body portion, said protective base coating being formed by chromium carbide (Cr3C2) and Nickel-Chrome (NiCr), or by Nickel-Chrome (NiCr), Iron (Fe), Molybdenum (Mo), Cobalt (Co), Manganese (Mn) and Aluminum (Al), and being obtained by deposition using spraying deposition techniques, preferably HVOF (High Velocity Oxygen Fuel) technique, HVAF (High Velocity Air Fuel) technique or KM (Kinetic Metallization) technique, and
a protective surface coating covers said at least one activated band body portion, said protective surface coating being formed by tungsten carbide (WC), iron (Fe), chrome (Cr) and aluminum (Al) and being obtained by depositing, on the protective base coating, tungsten carbide (WC), iron (Fe), chrome (Cr) and aluminum (Al), in particle form, using spraying deposition techniques, preferably HVOF (High Velocity Oxygen Fuel) technique, HVAF (High Velocity Air Fuel) technique or KM (Kinetic Metallization) technique,
and wherein the surface of said at least one activated band body portion coated with said protective base coating is defined by a nitro carburized layer of said base metal and has a rough profile in a radial or circumferential section with respect to a center of the braking band.

2. The braking band of claim 1 , wherein said first and second channel sides are parallel to each other.

3. The braking band of claim 1 , wherein at least one of the following features applies:
said first channel side forms an acute angle of 80° with said channel bottom,
said second channel side forms an obtuse angle of 100° with said channel bottom.

4. The braking band of claim 1 , wherein
said at least one pair of projections is a first projection that forms undercuts on both projection sides thereof;
or
said at least one pair of projections is a second projection that delimits second channel sides, both forming obtuse angles with respective channel bottoms;
or
said at least one pair of projections is a third projection that delimits the first channel side, forming an acute angle with the channel bottom and the second channel side, forming an obtuse angle with the channel bottom.

5. The braking band of claim 4 , wherein
said at least one pair of projections is a plurality of projections, which alternate, in particular, the first projection and the second projection;
or
said at least one pair of projections is a plurality of projections, which are all equal, in particular, a plurality of third projections;
or
said at least one pair of projections is a plurality of projections comprising
a first plurality of third projections and
a second plurality of third projections, the second plurality of third projections having a profile, that is a cross section at a longitudinal extension of each projection of said second plurality, opposite the profile of said first plurality, and
a second projection, interposed between said first and second pluralities.

6. The braking band of claim 4 , wherein at least one of the following features applies:
said at least one channel has a depth from 0.05 mm to 0.1 mm, and a width from 0.5 mm to 0.7 mm;
said first, second or third projection has a width identical to the width of said at least one channel;
said channel bottom is a flat surface.

7. The braking band of claim 4 , wherein at least one of the following features applies:
said first, second or third projection is externally delimited by a projection ridge, wherein said projection ridge is a flat surface;
said first, second or third projection is externally delimited by a projection ridge and wherein said first and second channel sides are joined to said projection ridge with a connecting radius ranging from 0.1 mm to 0.4 mm;
said first and second channel sides are joined to said channel bottom with a connection and wherein said connection has a connecting radius ranging from 0.01 mm to 0.02 mm.

8. The braking band of claim 1 , wherein a first projection forming undercuts on both sides thereof and a second projection delimiting second channel sides, both forming obtuse angles with respective channel bottoms, alternate to form a plurality of channels in said rough profile.

9. A disk for a disk brake comprising the braking band of claim 1 and a bell associated with said braking band and configured to connect to a hub of a wheel of a vehicle.

10. A vehicle comprising the disk for a disk brake of claim 9 .

11. A method for producing a braking band, the method comprising:
providing a braking band comprising at least one braking surface, the braking band being made with an annular band body made of one of gray cast iron, steel, aluminum or alloys thereof;
subjecting at least one portion of said at least one braking surface to a processing for increasing surface roughness thereof by removing swart or by laser engraving or by plastic deformation, forming an activated band body portion;
producing said activated band body portion on a surface of said annular band body, making a rough profile;
making said rough profile with at least one channel delimited by at least one pair of projections;
extending said at least one channel along a path, which at least partially surrounds a rotation axis (X-X);
making said at least one channel so that a cross section thereof at a longitudinal extension thereof comprises a channel body and two opposite channel sides, namely a first channel side forming an acute angle with said channel bottom, that is an angle smaller than 90°;
a second channel side forming an obtuse angle with said channel bottom, that is an angle larger than 90°; and
depositing, on said activated band body portion, at least one protective coating comprising at least one material with elevated resistance to abrasion,
further comprising:
nitro carburizing said activated band body portion, obtaining a nitro carburized surface layer on the surface of said activated band body portion;
depositing, on said nitro carburized surface layer, a material, in particle form, made up of:
chromium carbide (Cr3C2)

Assignees

• Brembo Spa

Inventors

• Giammarinaro Salvatore
• Medici Stefano
• Biondo Simone
• Carminati Fabiano

Classifications

• F16D2250/0046

  Coating · CPC title

• F16D2200/0078

  laminated · CPC title

• F16D69/027

  Compositions based on metals or inorganic oxides · CPC title

• F16D2250/0092

  Tools or machines for producing linings · CPC title

• F16D2200/0026

  Non-ferro · CPC title