Wheel cylinder
OwnerManuel Barbosainventor
Life of this patent
Estimating the term…
Abstract
A wheel cylinder assembly for drum brake system. The wheel cylinder assembly includes a housing that defines a piston bore. A seal groove that is sized to receive an annular seal is formed into the piston bore. A piston is disposed in the piston bore and through the seal such that the seal sealingly engages both the housing and the piston. The construction of the wheel cylinder is such that honing and/or roller burnishing of the piston bore is not required.
Claims19
A wheel cylinder assembly comprising:
- a housing defining a bore, the bore having a cylindrical inner wall into which is a seal groove is formed, the inner wall having a surface finish having a roughness that is greater than about 1.6 μm (63μ inch) Ra;
- a cylindrical piston disposed at least partially in the bore and having an outside diameter, the outside diameter having a surface finish with a roughness that is less than about 0.8 μm (32μ inch) Ra;
- and
- an annular seal disposed in the seal groove and sealingly engaging the outside diameter of the piston.
A drum brake system comprising a first brake shoe, a second brake shoe and a wheel cylinder for moving the first and second brake shoes relative to one another, the wheel cylinder including a housing, a cylindrical piston and a seal ring, the housing defining a bore having a cylindrical inner wall into which is a seal groove is formed, the inner wall having a surface finish having a roughness that is greater than about 1.6 μm (63μ inch) Ra, the piston being disposed at least partially in the bore and having a surface finish with a roughness of about 0.8 μm (32μ inch) Ra to about 0.05 μm (2μ inch) Ra, the annular seal being disposed in the seal groove and sealingly engaging an outside diameter of the piston.
Dependencies are inferred from the claim text.