Thermal protection for disc brake components

Abstract

A disc brake for a motor vehicle is provided. The disc brake includes a brake disc, a brake caliper configured to straddle the brake disc, a tappet carried by the brake caliper and arranged to push a brake pad against the brake disc, and a bellows provided between the brake caliper and the tappet to seal a gap between the brake caliper and the tappet. A layer of flexible thermal insulation material may be provided between the bellows and the tappet. The layer of flexible thermal insulation material is configured to protect an outer surface of the bellows facing the brake pad from exposure to heat. Alternatively, the bellows may include a layer of flexible thermal insulation material on which an elastomer layer is formed. The layer of flexible thermal insulation material is configured to face the brake pad.

What is claimed is: 
     
       1. A disc brake for a motor vehicle, the disc brake comprising:
 a brake disc; 
 a brake caliper configured to straddle the brake disc; 
 a tappet carried by the brake caliper and arranged to push a brake pad against the brake disc; and 
 an air gap located between the tappet and the caliper, the air gap varying in size as the tappet extends from a fully retracted position away from the brake disc to a fully extended position closer to the brake disc; and  
 a bellows provided extending across the air gap between the brake caliper and the tappet to seal a the air gap between the brake caliper and the tappet, 
 wherein the bellows comprises: 
 a first layer of non-metallic flexible thermal insulation material; and 
 a first elastomer layer formed on a first surface of the first layer of non-metallic flexible thermal insulation material such that a first surface of the first elastomer layer contacts the first surface of the first layer of non-metallic flexible thermal insulation material, 
 wherein a second surface of the first layer of non-metallic flexible thermal insulation material opposing the first surface is exposed to and faces the brake pad, and 
 wherein a second surface of the first elastomer layer is exposed to and faces an the air gap on a side of the first elastomer layer facing away from the brake disc. 
 
     
     
       2. The disc brake according to  claim 1 , wherein the flexible thermal insulation material is a woven or knitted material. 
     
     
       3. The disc brake according to  claim 2 , wherein the woven or knitted material comprises silica yarns, a combination of silica and fiberglass yarns, or basalt yarns. 
     
     
       4. The disc brake according to  claim 1 , wherein the elastomer layer comprises silicon rubber. 
     
     
       5. The disc brake according to  claim 1 , wherein the bellows further comprises:
 a second layer of flexible thermal insulation material; and   a second elastomer layer formed on a first surface of the second layer of flexible thermal insulation material,   wherein the first elastomer layer and the second elastomer layer are separated by the air gap.   
     
     
       6. The disc brake according to  claim 1 , wherein the bellows further comprises:
 a second layer of flexible thermal insulation material; and   a second elastomer layer formed on a first surface of the second layer of flexible thermal insulation material,   wherein the first elastomer layer and the second elastomer layer are joined by a plurality of additional elastomer layers to form a series of stacked discs.   
     
     
       7. A bellows for protecting internal components of a disc brake for a motor vehicle, the bellows comprising:
 a first layer of non-metallic flexible thermal insulation material; and 
 a first elastomer layer formed on a first surface of the first layer of non-metallic flexible thermal insulation material such that a first surface of the first elastomer layer contacts the first surface of the first layer of non-metallic flexible thermal insulation material, 
 wherein a second surface of the first layer of non-metallic flexible thermal insulation material opposing the first surface is exposed to and faces a heat source of the disc brake, and 
 wherein a second surface of the first elastomer layer faces an air gap on a side of the first elastomer layer facing away from the brake disc. 
 
     
     
       8. The bellows according to  claim 7 , wherein the flexible thermal insulation material is a woven or knitted material. 
     
     
       9. The bellows according to  claim 8 , wherein the woven or knitted material comprises silica yarns, a combination of silica and fiberglass yarns, or basalt yarns. 
     
     
       10. The bellows according to  claim 7 , wherein the elastomer layer comprises silicon rubber. 
     
     
       11. The bellows according to  claim 7 , further comprising:
 a second layer of flexible thermal insulation material; and   a second elastomer layer formed on a first surface of the second layer of flexible thermal insulation material,   wherein the first elastomer layer and the second elastomer layer are separated by the air gap.   
     
     
       12. The bellows according to  claim 7 , further comprising:
 a second layer of flexible thermal insulation material; and   a second elastomer layer formed on a first surface of the second layer of flexible thermal insulation material,   wherein the first elastomer layer and the second elastomer layer are joined by a plurality of additional elastomer layers to form a series of stacked discs.   
     
     
       13. An axle for a motor vehicle, the axle comprising a disc brake, wherein the disc brake comprises:
 a brake disc; 
 a brake caliper configured to straddle the brake disc; 
 a tappet carried by the brake caliper and arranged to push a brake pad against the brake disc; and 
 an air gap located between the tappet and the caliper, the air gap varying in size as the tappet extends from a fully retracted position away from the brake disc to a fully extended position closer to the brake disc; and  
 a bellows provided extending across the air gap between the brake caliper and the tappet to seal a the air gap between the brake caliper and the tappet, 
 wherein the bellows comprises: 
 a first layer of non-metallic flexible thermal insulation material; and 
 a first elastomer layer formed on a first surface of the first layer of non-metallic flexible thermal insulation material such that a first surface of the first elastomer layer contacts the first surface of the first layer of non-metallic flexible thermal insulation material, 
 wherein a second surface of the first layer of non-metallic flexible thermal insulation material opposing the first surface is exposed to and faces the brake pad, and 
 wherein a second surface of the first elastomer layer is exposed to and faces an the air gap on a side of the first elastomer layer facing away from the brake disc. 
 
     
     
       14. A disc brake for a motor vehicle, the disc brake comprising:
 a brake disc;   a brake caliper configured to straddle the brake disc;   a tappet carried by the brake caliper and arranged to push a brake pad against the brake disc;   an air gap located between the tappet and the caliper, the air gap varying in size as the tappet extends from a fully retracted position away from the brake disc to a fully extended position closer to the brake disc;   a layer of non-metallic flexible thermal insulation material extending across the air gap between the tappet and the caliper; and   an elastomer layer configured to seal the air gap when the tappet is in the fully retracted position, the fully extended position, and any intermediate position, the elastomer layer being formed such that a first surface of the elastomer layer contacts at least a portion of a first surface of the layer of non-metallic flexible thermal insulation material in the fully retracted position,   wherein a second surface of the layer of non-metallic flexible thermal insulation material opposing the first surface is exposed to and faces the brake pad,   wherein a second surface of the elastomer layer is exposed to the air gap on a side of the elastomer layer facing away from the brake disc, and   wherein the layer of non-metallic flexible thermal insulation material is arranged to shield the entire first surface of the elastomer layer from heat when the tappet is in the fully retracted position, the fully extended position, and any intermediate position.   
     
     
       15. The disc brake according to claim 14, wherein the flexible thermal insulation material is a woven or knitted material. 
     
     
       16. The disc brake according to claim 15, wherein the woven or knitted material comprises silica yarns, a combination of silica and fiberglass yarns, or basalt yarns. 
     
     
       17. The disc brake according to claim 14, wherein the elastomer layer comprises silicon rubber. 
     
     
       18. An axle for a motor vehicle, the axle comprising a disc brake, wherein the disc brake comprises:
 a brake disc;   a brake caliper configured to straddle the brake disc;   a tappet carried by the brake caliper and arranged to push a brake pad against the brake disc;   an air gap located between the tappet and the caliper, the air gap varying in size as the tappet extends from a fully retracted position away from the brake disc to a fully extended position closer to the brake disc;   a layer of non-metallic flexible thermal insulation material extending across the air gap between the tappet and the caliper;   an elastomer layer configured to seal the air gap when the tappet is in the fully retracted position, the fully extended position, and any intermediate position, the elastomer layer being formed such that a first surface of the elastomer layer contacts at least a portion of a first surface of the layer of non-metallic flexible thermal insulation material in the fully retracted position,   wherein a second surface of the layer of non-metallic flexible thermal insulation material opposing the first surface is exposed to and faces the brake pad,   wherein a second surface of the elastomer layer is exposed to the air gap on a side of the elastomer layer facing away from the brake disc, and   wherein the layer of non-metallic flexible thermal insulation material is arranged to shield the entire first surface of the elastomer layer from heat when the tappet is in the fully retracted position, the fully extended position, and any intermediate position.   
     
     
       19. The axle according to claim 18, wherein the elastomer layer is formed so as to be folded within the air gap in the fully retracted position and unfolded as the tappet moves toward the fully extended position. 
     
     
       20. The axle according to claim 19, wherein the layer of non-metallic flexible thermal insulation material is arranged to prevent contact between the elastomer layer and the tappet when the tappet is in the fully retracted position, the fully extended position, and any intermediate position. 
     
     
       21. The disc brake according to claim 14, wherein the elastomer layer is formed so as to be folded within the air gap in the fully retracted position and unfolded as the tappet moves toward the fully extended position. 
     
     
       22. The disc brake according to claim 21, wherein the layer of non-metallic flexible thermal insulation material is arranged to prevent contact between the elastomer layer and the tappet when the tappet is in the fully retracted position, the fully extended position, and any intermediate position. 
     
     
       23. The bellows according to claim 7, wherein the first layer of non-metallic flexible thermal insulation material serves as a carrier material for the first elastomer layer.