Patent Description:
Disc brakes, in particular air disc brakes, are widely used in brake systems of utility vehicles, for example in heavy trucks, buses and trailers. An air disc brake comprises as essential parts a brake anchor plate, a brake caliper with a clamping unit, a brake cylinder and brake pads. The brake cylinder is fitted onto the brake caliper and is operated using compressed air provided by a compressed-air supply container, which is filled by a compressor. In case of a braking action, the brake cylinder provides via a lever an axial movement of a yoke and a push rod of the clamping unit, via which the brake pads are pushed to a brake disc, which is mounted onto an axle of a utility vehicle, to create friction.

<FIG> illustrates a brake caliper <NUM> including a clamping unit <NUM> of an air disc brake, as used for utility vehicles. The brake caliper <NUM> is arranged on guide pins of a brake anchor plate, not shown in <FIG>, which allows for an axial movement of the brake caliper <NUM> relative to the brake anchor plate in case of a braking action. To allow a smooth movement of the clamping unit <NUM> within the brake caliper <NUM>, two half shell bearings <NUM>, <NUM> are arranged between a lever <NUM>, shown in <FIG>, and the clamping unit <NUM>.

<FIG> shows the clamping unit <NUM> during assembly into the brake caliper <NUM> of the air disc brake. The clamping unit <NUM> includes a push rod <NUM>, a yoke <NUM> and an adjuster unit <NUM>, which are shifted by the lever <NUM> during a braking action to press brake pads, which are arranged on a brake anchor plate of the air disc brake, onto a brake disc. The half shell bearings <NUM>, <NUM> comprise a fixing means <NUM>, respectively <NUM>, via which the half shell bearings <NUM>, <NUM> are securely mounted on the clamping unit <NUM>.

<FIG> schematically depicts a cross section of the brake caliper <NUM> with the clamping unit <NUM> of <FIG>. The lever <NUM> is rotatable around a pivot axis <NUM>. The half shell bearing <NUM>, correspondingly also the half shell bearing <NUM>, are arranged between the clamping unit <NUM> and the lever <NUM>. The half shell bearing <NUM> comprises a bearing cage <NUM>, in which needle rollers <NUM> are inserted, and a bearing shell <NUM>. The bearing cage <NUM> is movably positioned within the bearing shell <NUM>. This can cause a problem during assembly of the brake caliper <NUM>, when the half shell bearing <NUM> is inserted into the brake caliper <NUM>, because the bearing cage <NUM> may collide with the lever <NUM> during insertion, at a location <NUM>, and then the half shell bearing <NUM> is not positioned correctly within the brake caliper <NUM>.

shows a correct position of the bearing cage <NUM>, but as in this position the bearing cage <NUM> is close to the brake caliper <NUM> during an assembly, the bearing cage <NUM> can hit an edge of the brake caliper <NUM>, which can move the bearing cage <NUM> into a not correct position.

<FIG> shows in a front view the half shell bearing <NUM> being used within the brake caliper <NUM> and as described with regard to <FIG>. The half shell bearing <NUM> includes the bearing shell <NUM> and the bearing cage <NUM>, in which the needle rollers <NUM> are arranged as rolling elements. The bearing cage <NUM> is movable in one direction on a rolling path <NUM> between a first end <NUM> and a second, opposite end <NUM> of the bearing shell <NUM> because of limiting walls <NUM>, <NUM> of the bearing shell <NUM>, and because of the needle rollers <NUM>, which force a moving direction for the bearing cage <NUM> in a direction perpendicular to a rotation axis of the needle rollers <NUM>.

The half shell bearing <NUM> is also known as a needle roller bearing. The needle rollers <NUM> are used to reduce friction of a rotating surface. The rolling path <NUM> is also known as a race or a raceway and represents an outer race of the half shell bearing <NUM>.

At the first end <NUM> of the bearing shell <NUM>, a retaining means <NUM> is provided at the bearing shell <NUM> to restrict the movement of the bearing cage <NUM> within the bearing shell <NUM> in the direction of the first end <NUM>. The second end <NUM> of the bearing shell <NUM> is open and does not restrict the movement of the bearing cage <NUM>. The fixing means <NUM> is arranged at a back side of the bearing shell <NUM> for mounting the half shell bearing <NUM> on the brake caliper <NUM>. The half shell bearing <NUM> is constructed in a similar manner as the half shell bearing <NUM>.

When the half shell bearing <NUM> is assembled at the brake caliper <NUM>, the bearing cage <NUM> has to be in a position within the bearing shell <NUM> as depicted in <FIG>. When the bearing cage <NUM> is in a position within the bearing shell <NUM> as depicted in <FIG>, the half shell bearing <NUM> may not be correctly positioned at the brake caliper <NUM>, as described before with regard to <FIG>.

In a state of the art design, during the assembly of the clamping unit <NUM> together with the half shell bearing <NUM> into the brake caliper <NUM>, and when the bearing cage <NUM> is in position like on <FIG> to not collide with the lever <NUM>, but also in this position, an edge of the bearing cage <NUM> can hit the brake caliper <NUM>. The bearing cage <NUM> can, therefore, move in the direction of the second end <NUM> and collide with the lever <NUM> during assembly, as the brake caliper <NUM> is close to the bearing cage <NUM>.

A disc brake comprising a brake anchor plate and a brake caliper with a clamping unit is disclosed in <CIT>. The clamping unit comprises a lever, which can be actuated by a brake cylinder via a piston. A half shell needle bearing is inserted between a cam of the lever and a brake actuation mechanism of the clamping unit, via which brake pads are pushed onto a brake disc in case of a braking action.

<CIT>, corresponding with <CIT>, discloses a disc brake comprising a brake anchor plate and a brake caliper with a clamping unit, which includes a half shell bearing.

<CIT> discloses a half shell bearing comprising a bearing shell and a bearing cage according to the preamble of claim <NUM>.

<CIT> discloses a half shell bearing comprising a bearing shell, on which a partially cylindrically curved rolling path is formed, and a bearing cage with needle rollers as rolling elements. The bearing shell is provided with at least one retaining means, which extends into an opening of the bearing cage, to reduce an unwanted falling apart of the bearing shell and the bearing cage, and thus of the half shell bearing during assembly within a brake caliper of a disc brake.

<CIT> discloses a half shell bearing comprising a bearing shell, on which a partially cylindrically curved rolling path is formed, and a bearing cage with needle rollers as rolling elements, wherein the bearing shell comprises a retaining means for releasably fixing the bearing cage in a transport position. This has the advantage that a damage of the half shell bearing during transport and mounting of the half shell bearing is reduced.

<CIT> and <CIT> discloses a half shell bearing wherein two corners of the bearing cage are rounded.

It is an object of the present invention to provide an improved half shell bearing that allows a safe mounting of the half shell bearing within a brake caliper of a disc brake.

The invention is as set out in the independent claims <NUM>, <NUM> and <NUM>.

The half shell bearing comprises a bearing shell and a bearing cage, wherein the bearing shell comprises a surface being designed as a rolling path for the bearing cage. The bearing shell further comprises two shell walls on opposite sides of the bearing shell, a third side with a retaining means for limiting a movement of the bearing cage, and a fourth side opposite to the third side. The bearing cage comprises cylindrical rolling elements that roll on the rolling path, wherein the bearing cage is movably accommodated on the rolling path within the shell walls of the bearing shell, and the bearing cage comprises two corners being directed to the third side of the bearing shell, wherein the two corners of the bearing cage are chamfered.

In a preferred embodiment, the rolling path of the bearing shell is constructed as a partially cylindrically curved surface.

In another preferred embodiment, the rolling elements are cylindrical rolling elements, for example needle elements, having a diameter and a length, wherein the diameter is small relative to the length.

In another preferred embodiment, the two shell walls of the bearing shell are designed to limit the movement of the bearing cage.

In another preferred embodiment, the bearing cage has a rectangular form with four corners, wherein all four corners are chamfered.

In another preferred embodiment, the bearing cage comprises an outer rolling element being located at an end of the bearing cage being directed to the third side of the bearing shell, an outer rolling element being located at an end of the bearing cage being directed to the fourth side of the bearing shell and inner rolling elements, wherein the outer rolling element being located at the end of the bearing cage being directed to the third side has a length, which is shorter than the length of the inner rolling elements.

In another preferred embodiment, the bearing cage comprises an outer rolling element being located at an end of the bearing cage being directed to the third side of the bearing shell, an outer rolling element being located at an end of the bearing cage being directed to the fourth side of the bearing shell and inner rolling elements, wherein both outer rolling elements have a length, which is shorter than the length of the inner rolling elements.

In another preferred embodiment, the fourth side of the bearing shell comprises an open end, which is not limiting a movement of the bearing cage.

In another preferred embodiment, the bearing shell comprises a fixing means for mounting the half shell bearing at a brake calliper of a disc brake.

The invention further defines a disc brake comprising a brake calliper with a clamping unit and a respective half shell bearing. The disc brake is in particular an air operated or electromechanically operated sliding calliper disc brake.

The disc brake is advantageously used within a compressed air brake system of a utility vehicle.

Preferred embodiments of the disclosure are explained in more detail below by way of example with reference to schematic drawings, which show:.

The present description illustrates the principles of the present invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its scope.

All examples and conditional language recited herein are intended for instructional purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventors to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof.

<FIG> depicts a half shell bearing <NUM> according to the prior art, comprising a bearing shell <NUM> and a bearing cage <NUM>. The bearing cage <NUM> includes cylindrical rolling elements <NUM>, in particular needle rollers as the rolling elements <NUM>, to allow a movement of the bearing cage <NUM> on a surface of the bearing shell <NUM>, which is designed as a rolling path <NUM> for the bearing cage <NUM>. The bearing shell <NUM> comprises limiting shell walls <NUM> and <NUM> on opposite sides of the bearing shell <NUM>, to restrict the movement of the bearing cage <NUM> on the rolling path <NUM> to one dimension, in a direction perpendicular to a rotation axis of the rolling elements <NUM>. The bearing shell <NUM> and a bearing cage <NUM> are cylindrically curved and the rolling path <NUM> is formed in particular as a partially cylindrically curved rolling path on the bearing shell <NUM>. The cylindrical rolling elements <NUM> constitute bearing elements that are small in diameter relative to their length.

At a third side <NUM> of the bearing shell <NUM>, two hooks are arranged as a retaining means <NUM>, <NUM>. The retaining means <NUM>, <NUM> provide an end of the rolling path <NUM>, for restricting a movement of the bearing cage <NUM> in the direction of the third side <NUM>. The bearing shell <NUM> further comprises a fourth side <NUM> opposite to the third side <NUM>, which does not restrict the movement of the bearing cage <NUM>. At the third side <NUM>, at the back of the bearing shell <NUM>, not visible in <FIG>, a further hook is provided as a fixing means <NUM> for the half shell bearing <NUM>, to allow a mounting of the half shell bearing <NUM> within a brake caliper of a disc brake.

The bearing cage <NUM> has in particular a rectangular form with four corners <NUM>-<NUM>. The two corners <NUM>, <NUM> are located at an end <NUM> of the bearing cage <NUM> in the direction of the third side <NUM> of the bearing shell <NUM> and the two corners <NUM>, <NUM> are located at an end <NUM> of the bearing cage <NUM> in the direction of the fourth side <NUM> of the bearing shell <NUM>, wherein at least the two corners <NUM>, <NUM> of the end <NUM>, located at the third side <NUM> of the bearing shell <NUM>, are rounded.

In the embodiment of <FIG>, all four corners <NUM>-<NUM> of the bearing cage <NUM> are rounded. This has the advantage that a wrong assembly of the bearing cage <NUM> within the bearing shell <NUM> is avoided, in the sense of a poka yoke design.

A further embodiment of a half shell bearing <NUM> according to the invention is depicted in <FIG>. The half shell bearing <NUM> comprises a bearing shell <NUM> and a bearing cage <NUM>, wherein the bearing shell <NUM> is similar in size and form to the bearing shell <NUM>, or is identical with the bearing shell <NUM>. The bearing cage <NUM> comprises rolling elements <NUM>, which correspond with the rolling elements <NUM>, or are identical with the rolling elements <NUM>.

The bearing shell <NUM> comprises in particular limiting shell walls <NUM> and <NUM> on opposite sides of the bearing shell <NUM>, to restrict the movement of the bearing cage <NUM> on a rolling path <NUM> to one dimension, in a direction perpendicular to a rotation axis of the rolling elements <NUM>.

At a third side <NUM> of the bearing shell <NUM>, two hooks are arranged as a retaining means <NUM>, <NUM>, defining an end of the rolling path <NUM>, for restricting a movement of the bearing cage <NUM> in the direction of the third side <NUM>. The bearing shell <NUM> comprises further a fourth side <NUM>, which does not restrict the movement of the bearing cage <NUM>.

The bearing cage <NUM> has a rectangular form with four corners <NUM>-<NUM> and is similarly constructed as the bearing cage <NUM>. The two corners <NUM>, <NUM> are located at an end <NUM> in the direction of the third side <NUM> of the bearing shell <NUM> and the two corners <NUM>, <NUM> are located at an end <NUM> in the direction of the fourth side <NUM> of the bearing shell <NUM>, wherein at least the two corners <NUM>, <NUM> of the end <NUM>, located at the third side <NUM> of the bearing shell <NUM>, are chamfered.

In the embodiment of <FIG>, all four corners <NUM>-<NUM> of the bearing cage <NUM> are chamfered. This has the advantage that a wrong assembly of the bearing cage <NUM> within the bearing shell <NUM> is avoided.

The half shell bearing <NUM> has the advantage that the bearing cage <NUM> is smaller at the ends <NUM> and <NUM> because of the chamfered corners <NUM>-<NUM>. Correspondingly, also the danger that the bearing cage <NUM> collides with a brake caliper of a disc brake during insertion of the half shell bearing <NUM> into a clamping unit of the disc brake is reduced.

<FIG> illustrates a detail of a brake caliper <NUM> with a clamping unit <NUM> of an air disc brake in an enlarged view, after the half shell bearing <NUM> is inserted into the brake caliper <NUM>. Because the size of the bearing cage <NUM> is reduced at the fourth side <NUM> of the half shell bearing <NUM> due to the rounded corners <NUM>, <NUM>, there is an increased space, compared to <FIG>, between the bearing cage <NUM> and the brake caliper <NUM> at a location <NUM>. Therefore, the danger that the bearing cage <NUM> collides with the brake caliper <NUM> is reduced.

When the half shell bearing <NUM> is inserted into the brake caliper <NUM>, correspondingly, also the danger that the bearing cage <NUM> of the half shell bearing <NUM> collides with the brake caliper <NUM> is reduced, because the bearing cage <NUM> is smaller at the end being directed to the fourth side <NUM> of the bearing shell <NUM> due to the chamfered corners <NUM>, <NUM>.

A further embodiment of a half shell bearing <NUM> according to the invention is depicted in <FIG>. The half shell bearing <NUM> comprises a bearing shell <NUM> and a bearing cage <NUM>, wherein the bearing shell <NUM> is similar in size and form to the bearing shell <NUM> or is identical with the bearing shell <NUM>. The bearing shell <NUM> comprises in particular limiting shell walls <NUM> and <NUM> on opposite sides of the bearing shell <NUM>, to restrict the movement of the bearing cage <NUM> on a rolling path <NUM> of the bearing shell <NUM> to one dimension. The bearing cage <NUM> comprises four corners <NUM>-<NUM>, which are chamfered.

The bearing cage <NUM> comprises inner rolling elements <NUM> and outer rolling elements <NUM> and <NUM>', which are small in diameter relative to their length. In this embodiment, the outer rolling elements <NUM>, <NUM>' have a length, which is shorter than the length of the inner rolling elements <NUM>. This has the advantage that the four corners <NUM>-<NUM> can be more, stronger chamfered compared to the four corners <NUM>-<NUM> of the bearing cage <NUM>. Therefore, the bearing cage <NUM> is smaller at ends <NUM>, <NUM> of the bearing cage <NUM> compared to the ends <NUM>, <NUM> of the bearing cage <NUM>.

<FIG> illustrates a detail of the brake caliper <NUM> with the clamping unit <NUM> in an enlarged view, after the half shell bearing <NUM> is inserted into the brake caliper <NUM>. Because the size of the bearing cage <NUM> is further reduced at both ends <NUM>, <NUM> , compared to the bearing cages <NUM> and <NUM>, there is in particular more open space, compared to <FIG>, between the bearing cage <NUM> and the brake caliper <NUM> at the location <NUM>, and the danger that the bearing cage <NUM> collides with the brake caliper <NUM> is further reduced.

The half shell bearing <NUM> has the advantage that the width of the bearing cage <NUM> is even smaller at the end <NUM> being directed to the third side <NUM> and at the end <NUM> being directed to the fourth side <NUM> of the bearing shell <NUM> with regard to the bearing cages <NUM> and <NUM>, and therefore, the danger that the bearing cage <NUM> collides with the brake caliper <NUM> during insertion of the half shell bearing <NUM> into the clamping unit <NUM> of the brake caliper <NUM> is further reduced.

Claim 1:
A half shell bearing (<NUM>; <NUM>; <NUM>) comprising a bearing shell (<NUM>; <NUM>; <NUM>) and a bearing cage (<NUM>; <NUM>; <NUM>), wherein
the bearing shell (<NUM>; <NUM>; <NUM>) comprises a surface being designed as a rolling path (<NUM>; <NUM>; <NUM>) for the bearing cage (<NUM>; <NUM>; <NUM>);
the bearing shell (<NUM>; <NUM>; <NUM>) comprises two shell walls (<NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>) on opposite sides of the bearing shell (<NUM>; <NUM>; <NUM>), a third side (<NUM>; <NUM>; <NUM>) with a retaining means (<NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>) for limiting a movement of the bearing cage (<NUM>; <NUM>; <NUM>), and a fourth side (<NUM>; <NUM>; <NUM>) opposite to the third side (<NUM>; <NUM>; <NUM>);
the bearing cage (<NUM>; <NUM>; <NUM>) comprises cylindrical rolling elements (<NUM>; <NUM>; <NUM>, <NUM>, <NUM>') that roll on the rolling path (<NUM>; <NUM>; <NUM>), wherein the bearing cage (<NUM>; <NUM>; <NUM>) is movably arranged on the rolling path (<NUM>; <NUM>; <NUM>) within the shell walls (<NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>) of the bearing shell (<NUM>; <NUM>; <NUM>); and
the bearing cage (<NUM>; <NUM>; <NUM>) comprises two corners (<NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>) at an end (<NUM>;<NUM>; <NUM>) of the bearing cage (<NUM>; <NUM>; <NUM>) being directed to the third side (<NUM>; <NUM>; <NUM>) of the bearing shell (<NUM>; <NUM>; <NUM>);
characterized in that
the two corners (<NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>) of the bearing cage (<NUM>; <NUM>; <NUM>) are chamfered.