A brake device includes a brake caliper with a first frictional surface and a first actuation surface, a pressing part of the brake device being linearly guided along a first straight line on the brake caliper. The pressing part has a second frictional surface and a second actuation surface, a region being provided between the first frictional surface and the second frictional surface for arranging a brake element. The brake device has a rotatable spreading element which interacts with the first actuation surface and the second actuation surface. During a rotation of the spreading element, the rotation occurring in order to actuate the brake device, a first spreading element surface is in direct contact with a first rolling surface and rolls substantially on the first rolling surface, and the first rolling surface corresponds to the first actuation surface or the second actuation surface.
1. A brake device comprising:
a brake caliper having a first leg, a second leg and a connecting section connecting the first leg to the second leg;
wherein a first frictional surface is arranged on a first inner side of the first leg, and a first actuation surface is arranged on a second inner side of the second leg;
wherein a pressing part of the brake device on the brake caliper is linearly guided along a first straight line;
wherein the pressing part has a second frictional surface facing the first frictional surface and a second actuation surface faces away from the second frictional surface;
wherein a region between the first frictional surface and the second frictional surface is provided for the arrangement of a brake element;
wherein the brake device has a rotatable spreading element which interacts with the first actuation surface and the second actuation surface;
wherein, when the spreading element is rotated to actuate the brake device, a first spreading element surface is in direct contact with a first rolling surface and rolls substantially on the first rolling surface, and that the first rolling surface corresponds to the first actuation surface or the second actuation surface;
wherein a profile of the first spreading element surface forms a first rolling curve;
wherein the first rolling curve has at least one center of curvature;
wherein, with at least 80% of an operating angle range of the rotation of the spreading element that takes place to actuate the brake device, the axis of rotation of the spreading element is arranged in front of the center of curvature of a point of contact viewed from the point of contact of the first rolling curve in a direction of the first straight line; and
wherein the first rolling surface spans a plane normal to the first straight line, the spreading element, the pressing part, and the brake caliper arranged so that a further axis of rotation of the spreading element in a starting position and another axis of rotation of the spreading element in an end position are arranged on opposite sides of the plane of the rolling surface.
2. The brake device according to claim 1 , wherein, in order to rotate the spreading element, the spreading element is operatively connected to an electric motor via an actuation mechanism.
3. The brake device according to claim 2 , wherein the actuation mechanism comprises a non-linear translation between a rotation of the electric motor and a rotation of the spreading element.
4. The brake device according to claim 1 , wherein:
on one edge of the first rolling surface, a support surface is integrally formed which is arranged obliquely to the first rolling surface for the first spreading element surface; and
the support surface supports the first spreading element surface in a starting position of the spreading element against forces transverse to the first straight line.
5. The brake device according to claim 1 , wherein the first rolling curve is substantially a circular arc.
6. The brake device according to claim 1 , wherein the spreading element is mounted on a second spreading element surface in a roller bearing, on the actuation surface which is not the first rolling surface.
7. The brake device according to claim 6 , wherein the roller bearing is a needle bearing.
8. The brake device according to claim 6 , wherein the roller bearing is at least partially in the shape of a cylinder jacket.
9. The brake device according to claim 1 , wherein, when the spreading element rotates to actuate the brake device, a second spreading element surface is in direct contact with a second rolling surface and substantially rolls on the second rolling surface, and the second rolling surface corresponds to the actuation surface which is not the first rolling surface.
10. The brake device according to claim 1 , wherein the spreading element has a guide at its axis of rotation, and the guide supports the axis of rotation of the spreading element against forces transverse to the first straight line, at least in an initial range of the rotation of the spreading element against the brake caliper for actuating the brake device.
11. The brake device according to claim 1 , wherein the pressing part comprises a wear adjuster, and the first actuation surface is divided into two parts and is arranged on both sides of the wear adjuster.
12. The brake device according to claim 1 , wherein the brake device has a guide receiving area for connection to a bearing component with the formation of a bearing of the brake device which can be displaced in the direction of a first straight line.
13. The brake device according to claim 12 , wherein a movement damping part coupled to the spreading element for damping a translational movement of the spreading element with respect to the bearing component is formed in the guide receiving area parallel to the first straight line.
14. Wheel bearing comprising a brake disk as a brake element and a brake device according to claim 1 , wherein an axis of rotation of the brake disk runs parallel to the first straight line.
15. A vehicle comprising at least one wheel bearing according to claim 14 .