Electromechanically actuatable brake piston assembly

Abstract

The invention relates to an electromechanically actuatable brake piston assembly. The brake piston assembly includes: a brake caliper housing including a first rolling bearing seat; a brake piston; a driving screw; and a rolling bearing having a rolling element guide and having a plurality of rolling elements which roll on a first raceway comprised by the rolling element guide and a second raceway comprised by the second rolling bearing, the rolling element guide having a first support surface by means of which the rolling element guide is supported by the first rolling element guide and by means of which the rolling element guide is supported by the second rolling bearing. The rolling element guide is supported in the axial direction against the first contact surface of the first rolling bearing seat, and wherein the rolling element guide has a second support surface by means of which the rolling element guide is supported in the radial direction against the second contact surface of the first rolling bearing seat, and wherein the rolling element guide has a second support surface by means of which the rolling element guide is supported in the radial direction against the second contact surface of the first rolling bearing seat. And / or by means of the second support surface, the rolling element guide is held in a form-locked manner by the first rolling bearing seat in the radial direction.

Description

Field of the Invention

[0001] The present invention relates to an electromechanically actuable brake piston assembly for a motor vehicle disc brake. The present invention also relates to a motor vehicle disc brake having a brake piston assembly of this type and having an electromechanical drive. Background Art

[0002] This type of brake piston assembly serves to support a brake piston for axial movement, the brake piston being received in a recess of a brake caliper housing, and to provide the brake piston such that it can be actuated by an electromechanical drive. In this way, the brake piston can transmit a pressing force to a brake lining, which in turn can press against a brake rotor with the pressing force and can brake the brake rotor. The axial movement of the brake piston is usually achieved by means of a spindle drive mounted in the brake piston. In this case, the brake piston has an anti-rotation mechanism such that the brake piston driven by the spindle can move translationally. The spindle is usually supported in the brake caliper housing, in particular in the bottom of the recess, such that the pressing force generated when the brake piston assembly or the associated motor vehicle disc brake is actuated can be guided into the brake caliper housing by means of a bearing system. Thus, the spindle is usually supported by means of an axial bearing. Summary of the Invention

[0003] It is an object of the present invention to provide an electromechanically actuable brake piston assembly for a motor vehicle disc brake, which brake piston assembly is relatively easy to assemble, in which frictional losses in the region of the spindle bearing system are reduced, and in which the brake caliper housing permanently withstands the acting forces.

[0004] According to the present invention, the object is achieved by the brake piston assembly and the motor vehicle disc brake of the present invention.

[0005] The electromechanically actuable brake piston assembly according to the present invention is provided for a motor vehicle disc brake and has a brake caliper housing. When in the following description only the term "brake piston assembly" is used without the preceding expression "electromechanically actuable" for better readability, this should always be understood as referring to the electromechanically actuable brake piston assembly. The brake caliper housing includes a recess, which is bounded by a recess bottom and a recess wall extending into the brake caliper housing, wherein the recess has a recess opening opposite the recess bottom. The recess bottom has a shaft guide hole and a first rolling bearing seat.

[0006] The brake piston assembly includes a brake piston that is supported in a recess for axial movement. The brake piston has an end wall with which the brake piston projects from the recess opening or can be moved out of the brake caliper housing through the recess opening. The brake piston includes a brake piston wall that surrounds an internal space and has an interior facing the internal space, wherein at least one internal thread is formed in the interior. The expression "axial" or in the "axial direction" relates to the direction of extension of the recess into the brake caliper housing and to the direction of movement of the brake piston towards or away from the brake disc associated when the brake piston assembly is installed in a disc brake. That is, the axial direction extends transversely to the braking surface of the associated brake disc.

[0007] The brake piston assembly further includes a drive screw that includes: a threaded portion having at least one external thread; a shaft that extends through the shaft guide hole; and a second rolling bearing seat that is arranged in a transition region from the shaft to the threaded portion, wherein the at least one external thread is operatively connected to the at least one internal thread for driving such that the drive screw and the brake piston together function as a screw drive.

[0008] The brake piston assembly further includes a rolling bearing that has a rolling element guide and a plurality of rolling elements. The rolling elements roll on a first raceway included by the rolling element guide and a second raceway included by the second rolling bearing seat. The rolling element guide has a first support surface by means of which the rolling element guide is supported axially against a first contact surface of the first rolling bearing seat.

[0009] The rolling element guide further has a second support surface by means of which the rolling element guide is supported radially against a second contact surface of the first rolling bearing seat or by means of which the rolling element guide is held in form-fit in the radial direction by the first rolling bearing seat. The radial support and the form-fit can also exist in combination.

[0010] Preferably, the bottom of the recess includes a first surface portion facing the recess and a projection extending into the recess. In this case, the projection includes the first rolling bearing seat, and the first rolling bearing seat is closer to the recess opening than the first surface portion.

[0011] Preferably, the projection includes a second surface portion connecting the first surface portion and the first contact surface to each other, wherein the second surface portion includes a second contact surface, and the second contact surface abuts the first contact surface. This has the effect of providing a good seat for the rolling element guide on the projection, which prevents the rolling element guide or other parts from making grinding contact with the screw. As a result, frictional losses are reduced. This design also makes the installation of the rolling element guide and other rolling bearing components relatively easy. The good placement of the rolling element guide on the projection also ensures a lasting functional ability.

[0012] Preferably, the second surface portion is cylindrical and has a first diameter, and the second contact surface is also preferably cylindrical and has a second diameter. In this case, the second diameter is smaller than the first diameter. By this measure, a particularly precise seat for the rolling element guide is achieved, resulting in a long service life of the brake piston assembly. The advantages of relatively easy assembly and low frictional losses are also provided.

[0013] In an embodiment of the present invention, the first rolling bearing container includes an annular flange having a flange inner portion, a flange outer portion, and an end face connecting the flange inner portion and the flange outer portion and facing the recess opening. The area of the first rolling bearing seat not covered by the annular flange includes a first contact surface. The end face is closer to the recess opening than the first contact surface. When referring to the area of the rolling bearing seat not covered by the annular flange, it is assumed that the first contact surface is observed axially.

[0014] Preferably, the first contact surface is arranged on the outer side of the flange in the radial direction, and the flange outer portion includes a second contact surface. "In the radial direction" means a direction or range extending transversely (especially orthogonally) to the axial direction. Therefore, in this case, the diameter defining the contact surface is larger than the diameter defining the flange. In the case where the contact surface transitions into the flange, the minimum diameter of the contact surface can be the same as the maximum diameter of the flange.

[0015] Alternatively, the first contact surface can be arranged on the inner side of the flange in the radial direction, and the flange inner portion can include a second contact surface.

[0016] Preferably, the rolling element guide is annular and disc-shaped and includes a first circumferentially extending curved portion. The first circumferentially extending curved portion includes a second support surface. This type of curved portion makes the rolling element guide easier to grasp and additionally provides a guiding surface, thus contributing to assembly friendliness. The curved portion also has a positive effect on the firm seating of the rolling element guide. The term "curved portion" is more a description of the geometric design rather than an indication of the specific method for manufacturing the rolling element guide. Therefore, this type of curved portion can be manufactured, for example, by deep drawing or by milling.

[0017] Preferably, the first circumferentially extending curved portion is located at the outer edge of the rolling element guide and faces away from the opening of the recess. The second support surface is located on the inside of the first circumferentially extending curved portion. Alternatively or additionally, the rolling element guide includes a second circumferentially extending curved portion at the inner edge of the rolling element guide, wherein the second circumferentially extending curved portion points towards the opening of the recess. Preferably, the second circumferentially extending curved portion radially guides at least a part of the rolling element. The statement "the first circumferentially extending curved portion is located at the outer edge of the rolling element guide and faces away from the opening of the recess" first means that: the rolling element guide has a radial extent (also as described above), and the curved portion is arranged in the outer region of the rolling element guide with respect to this radial extent, or at the outer diameter of the rolling element guide. Secondly, this means that: the curved portion results in a free-turning end or a circumferentially extending edge that is free to turn, which has an inner and an outer side. Due to the curved portion or the turn, this edge or the first circumferentially extending curved portion extends away from the opening of the recess. In this embodiment, the situation of the second circumferentially extending curved portion is the opposite of that of the first circumferentially extending curved portion. In the case of each circumferentially extending curved portion, logically, the inner side has a smaller diameter than the outer side.

[0018] In an alternative embodiment of the present invention, the first circumferentially extending curved portion is located at the outer edge of the rolling element guide and points towards the opening of the recess. The second support surface is located on the outside of the first circumferentially extending curved portion. As an alternative or supplement to the design described in the previous two sentences, the rolling element guide includes a second circumferentially extending curved portion at the inner edge of the rolling element guide, wherein the second circumferentially extending curved portion points towards the opening of the recess. Preferably, the second circumferentially extending curved portion radially guides at least a part of the rolling element.

[0019] In an alternative embodiment of the present invention, the first circumferentially extending curved portion is located at the inner edge of the rolling element guide and points towards the opening of the recess. The second support surface is located on the inside of the first circumferentially extending curved portion. As an alternative or supplement to the design described in the previous two sentences, the rolling element guide includes a second circumferentially extending curved portion at the outer edge of the rolling element guide, wherein the second circumferentially extending curved portion points towards the opening of the recess. Preferably, the second circumferentially extending curved portion radially guides at least a part of the rolling element.

[0020] In a preferred embodiment of the present invention, the rolling bearing is an axial rolling bearing, more preferably a needle bearing.

[0021] In a preferred embodiment of the present invention, the second rolling bearing housing includes a bearing ring and a third contact surface located between the threaded portion and the shaft. The bearing ring includes a second raceway and a second support surface opposite to the second raceway. That is, the second raceway and the second support surface are part of the bearing ring. The second support surface of the bearing ring is axially supported against the third contact surface directly or via a compensation ring. The third contact surface is preferably part of the drive screw.

[0022] Preferably, the projection is integrally joined to the brake caliper housing, and more preferably, the brake caliper housing is a cast part. In this way and especially in combination with the other mentioned inventive design possibilities of the present invention, a robust brake piston assembly is provided, in which the brake caliper housing permanently withstands the acting forces.

[0023] Particularly preferably, the at least one internal thread is in the form of an internal raceway, and the at least one external thread is in the form of an external raceway, wherein the electromechanically actuable brake piston assembly includes a plurality of balls that roll along the internal raceway and the external raceway such that the drive screw and the brake piston together act as a ball screw drive. This design constitutes a screw drive with almost no frictional losses.

[0024] A motor vehicle disc brake according to the present invention includes a brake carrier, an electromechanical drive, and a brake piston assembly according to the foregoing embodiments or combinations thereof, the electromechanical drive having a transmission assembly and an electric motor, and the brake piston assembly being actuable by the electromechanical drive. The foregoing advantages also apply to the motor vehicle disc brake. Description of the Drawings

[0025] Other features, advantages, and possible applications of the present invention are clear from the following description of the exemplary embodiments and from the schematic Figures 1 to 11 It is clear. For the sake of clarity, not all elements shown in the figures are always provided with reference numerals. However, the corresponding elements or regions are subsequently at least marked in another figure, in which their meaning can be found. Furthermore, in the figures, the same reference numerals may also denote the same or similar objects.

[0026] Figure 1 A first exemplary embodiment of a brake piston assembly according to the present invention is shown.

[0027] Figure 2 is a detailed view of the first exemplary embodiment.

[0028] Figure 3 A second exemplary embodiment of a brake piston assembly according to the present invention is shown.

[0029] Figure 4 is a detailed view of the second exemplary embodiment.

[0030] Figure 5 Shows a third exemplary embodiment of a brake piston assembly according to the present invention.

[0031] Figure 6 Is a detailed view of the third exemplary embodiment.

[0032] Figure 7 Shows a fourth exemplary embodiment of a brake piston assembly according to the present invention.

[0033] Figure 8 Is a detailed view of the fourth exemplary embodiment.

[0034] Figure 9 Shows a fifth exemplary embodiment of a brake piston assembly according to the present invention.

[0035] Figure 10 Is a detailed view of the fifth exemplary embodiment.

[0036] Figure 11 Shows an exemplary embodiment of a motor vehicle disc brake according to the present invention. Detailed Description

[0037] Figure 1 And Figure 2 Shows a first exemplary embodiment of a brake piston assembly 1 according to the present invention. The brake piston assembly 1 includes a brake caliper housing 5 having a recess 10. The recess 10 is formed by a recess bottom 15 and a cylindrical recess wall 11. The recess 10 opens at a point of the brake caliper housing 5 facing the brake disc axis 6 such that a brake piston 40 is disposed in the recess 10, the brake piston being guided by the recess wall 11 and an end wall 41 of the brake piston protruding from or being movable out of a corresponding recess opening 13. That is, when the brake piston assembly 1 is actuated, the brake piston 40 moves axially such that the end wall 41 moves toward the brake disc axis 6. In a fully assembled associated motor vehicle disc brake 100, this has the effect that the brake piston 40 moves a corresponding brake lining against a corresponding brake disc by means of the end wall 41 and brakes the brake disc. Of course, when the brake or the brake piston assembly 1 is released, the brake piston 40 can be moved further into the recess 10 again. At the same time, this allows or causes one or more associated brake linings to separate from the brake disc again.

[0038] The bottom 15 of the recess includes a first surface portion 18 that is arranged annularly around the cylindrical projection 20. The projection 20 extends from the first surface portion 18 towards the recess opening 13 to an extent such that the end face of the projection 20 is closer to the recess opening 13 than the first surface portion 18. The projection 20 is integrally joined to the brake caliper housing 5, which is generally a cast component. The cylindrical shaft guide hole 16 extends axially through the bottom 15 of the recess and the projection 20. This shaft guide hole 16 is a hole that extends coaxially with the recess 10. The first rolling bearing seat 25 includes a first contact surface 27 that is oriented perpendicular to the axial direction. The flange 30 rises from the contact surface 27 towards the recess opening 13 to an extent such that the end face 33 of the flange 30 is closer to the recess opening than the first contact surface 27. The flange 30 has a cylindrical flange interior 31 and a cylindrical flange exterior 32. The flange interior 31 and the flange exterior 32 define the flange width. The flange 30 is positioned such that the flange exterior 32 and the cylindrical outer wall of the projection 20 transition into each other and form a single cylindrical outer surface. The cylindrical outer wall of the projection 20 forms the first surface portion 18. In this exemplary embodiment, the flange interior 31 also simultaneously forms a second contact surface 28. The first contact surface 27 and the second contact surface 28 together form the first rolling bearing seat 25.

[0039] In addition to the end wall 41, the brake piston 40 also includes a cylindrical brake piston wall 42, the exterior of which is for guiding the brake piston 40 in the recess 10, and the interior 43 of which defines an interior space 48 in the brake piston 40. The inner raceway 44 of the ball screw drive 73 is formed in the interior 43. Thus, the brake piston 40 is cup-shaped, with the open side facing the bottom 15 of the recess, opposite the end wall 41.

[0040] The drive screw 55 is accommodated in the interior space 48. The drive screw 55 includes a threaded portion 56 having an outer raceway 57 of the ball screw drive 73, a shaft 63 that extends through the shaft guide hole 16, and a second rolling bearing seat 65 that is arranged in the transition region from the shaft 63 to the threaded portion 56. The outer raceway 57 is operatively connected to the inner raceway 44 and the corresponding balls 58 such that the drive screw 55 and the brake piston 40 together form the ball screw drive 73. The shaft 63 that extends through the shaft guide hole 16 can be driven on the drive side 7 by an electromechanical drive 105. Since the drive screw 55 is capable of rotating and the brake piston 40 is supported so as not to rotate, the brake piston 40 can move axially like a linear carriage.

[0041] The rolling bearing 75 in the form of an axial bearing is arranged between the first rolling bearing seat 25 and the second rolling bearing seat 65. The rolling bearing 75 includes an annular disc-shaped rolling element guide 80, which has a first support surface 92 and a first raceway 85 opposite to the first support surface 92. That is, the first support surface 92 and the first raceway 85 form two flat sides of the rolling element guide 80. The outer edge 81 forms the outer ring surface of the rolling element guide 80, and the inner edge 82 forms the inner ring surface. In this exemplary embodiment, the outer ring surface forms a second support surface 94. The first support surface 92 of the rolling element guide 80 is placed against the first contact surface 27, and the second support surface 94 of the rolling element guide is placed against the second contact surface 28. Thus, the rolling element guide 80 is located in a shape-locked manner in the recess formed by the flange 30 and the underlying first contact surface 27. Thereby, the rolling element guide 80 is firmly placed. Therefore, the inner edge 82 does not contact the shaft 63, thus avoiding kinetic friction between the shaft 63 and the rolling element guide 80.

[0042] In the transition region 60, the drive screw 55 has a third contact surface 61. The bearing ring 67 is placed against this contact surface 61. The side of the bearing ring 67 opposite to the contact surface 61 and facing the drive side 7 includes a second raceway 69, which is oriented orthogonally to the axial direction. The cylindrical rolling elements 77 are arranged between the first raceway 85 and the second raceway 69 and can roll along these two raceways 69, 85.

[0043] The shaft 63 is supported by a radial bearing in the region of the shaft guide hole 16.

[0044] Figure 3 and Figure 4Shows a second exemplary embodiment of the brake piston assembly 1 according to the present invention. The second exemplary embodiment differs from the first exemplary embodiment only in the design of the rolling bearing 75 and the rolling element guide 80. Therefore, for clarity, not all components that are the same as those of the first exemplary embodiment are provided with reference numerals in the drawings. In this regard, reference is made to the drawings of other exemplary embodiments. In the second exemplary embodiment, the rolling element guide 80 has a first circumferentially extending curved portion 86 at its outer edge 81. The main portion of the rolling element guide 80 having the first contact surface 27 and the first raceway 85 is oriented orthogonally to the axial direction, while the first circumferentially extending curved portion 86 extends a certain extent from the main portion of the rolling element guide 80 towards the recess opening 13. The first circumferentially extending curved portion 86 has an outer portion 88 and an inner portion 87 in the radial direction. In this exemplary embodiment, the outer portion 88 includes a second support surface 94. The rolling elements 77 are additionally guided by the first circumferentially extending curved portion 86. The rolling element guide 80 and the entire rolling bearing 75 are structurally compact and easy to grasp, thus facilitating assembly. The rolling elements are preferably needle rollers and preferably form a needle bearing together with other bearing components. In this exemplary embodiment, in addition to the bearing ring 67, the second rolling bearing seat 65 also has a compensation ring 70. In this case, the compensation ring 70 is placed against the third contact surface 61, and the bearing ring 67 includes a second raceway 69 and is arranged between the compensation ring 70 and the rolling elements 77.

[0045] Figure 5 and Figure 6 Shows a third exemplary embodiment of the brake piston assembly 1 according to the present invention. Here, with regard to the provision of reference numerals, components and elements that differ from other exemplary embodiments are again prioritized. Regarding the missing reference numerals, reference is made to the drawings of other exemplary embodiments. The difference between the third exemplary embodiment and the second exemplary embodiment lies in the design of the first rolling bearing seat 25 and the rolling element guide 80. Contrary to the first and second exemplary embodiments, here the flange 30 is positioned such that the inner flange 31 and the inner wall of the shaft guide hole 16 transition into each other. In this case, the first contact surface 27 is arranged annularly around the annular flange 30. The outer flange 32 includes a second contact surface 28. While in the first and second exemplary embodiments, the recess is formed by the flange 30, here there is an annular recess portion around the flange 30.

[0046] The rolling element guide 80 has a first circumferentially extending curved portion 86 at its inner edge 82. The main portion of the rolling element guide 80 having the first contact surface 27 and the first raceway 85 is oriented orthogonally to the axial direction, while the first circumferentially extending curved portion 86 extends from the main portion of the rolling element guide 80 towards the recess opening 13 to a certain extent. The first circumferentially extending curved portion 86 has an outer 88 and an inner 87 in the radial direction. In this exemplary embodiment, the inner 87 includes a second support surface 94. The rolling elements 77 are additionally guided by the first circumferentially extending curved portion 86. The rolling element guide 80 and the entire rolling bearing 75 are compact and easy to grasp, and thus facilitate assembly. The rolling elements are preferably needle rollers and preferably form a needle bearing together with other bearing components. The first support surface 92 of the rolling element guide 80 is placed against the first contact surface 27, and the second support surface 94 of the rolling element guide is placed against the second contact surface 28. Thus, the rolling element guide 80 is form-locked around the flange 30 and located in the recessed portion. Thereby, the rolling element guide 80 is firmly placed.

[0047] Figure 7 and Figure 8 A fourth exemplary embodiment of the brake piston assembly 1 according to the present invention is shown. The difference between the fourth exemplary embodiment and the second exemplary embodiment lies in the design of the first rolling bearing seat 25 and the rolling element guide 80. In this case, the projection 20 does not have a flange. That is, the first contact surface 27 is not reduced or interrupted by a flange. The cylindrical outer wall of the projection 20 (which forms the second surface portion 22) includes a second contact surface 28. The second contact surface completely abuts the first contact surface 27 which is an end face.

[0048] The rolling element guide 80 has at its outer edge 81 a first circumferentially extending curved portion 86 that extends a certain extent away from the main portion of the rolling element guide 80 towards the recess opening 13. The first circumferentially extending curved portion 86 has an outer 88 and an inner 87 in the radial direction. In this exemplary embodiment, the inner 87 includes a second support surface 94. That is, the rolling element guide 80 is form-fittingly engaged on the cylindrical projection, and the inner 87 of the rolling element guide or the second support surface 94 of the rolling element guide is disposed against the second contact surface 28 of the projection 20. In addition, the first support surface 92 of the rolling element guide 80 abuts against the first contact surface 27 of the projection 20 that serves as an end face. As a result of this design, the axial bearing component can be mounted relatively easily. In addition, the curved portion provides a fixed and permanent seat. Accidental sliding of the rolling element guide 80 and other bearing components is avoided, thus avoiding possible frictional losses. The rolling elements are preferably needle rollers and preferably form a needle roller bearing together with other bearing components. The rolling element guide 80 has at its inner edge 82 a second circumferentially extending curved portion 89 that extends a certain extent from the main portion of the rolling element guide 80 towards the recess opening 13. The rolling elements 77 are additionally guided by the second circumferentially extending curved portion 89.

[0049] Figure 9 and Figure 10 A fifth exemplary embodiment of the brake piston assembly 1 according to the invention is shown. The difference between the fifth exemplary embodiment and the fourth exemplary embodiment lies in the design of the projection 20 and the additional pressure equalization opening 8. The cylindrical second surface portion 22 is recessed in the region where the second contact surface 28 is located. That is, the diameter of the projection 20 is smaller in the region of the second contact surface 28 than in the remaining region of the second surface portion 22. Thus, the fit between the first curved portion 86 and its second support surface 94 on the inner 87 of the curved portion can be more precise, thereby achieving a better and more durable placement of the rolling element guide 80 on the projection 20. The described recessed second contact surface 28 can also be easily applied to the fourth exemplary embodiment.

[0050] Viewed in cross-section, the projection 20 forms a rectangular shape on each side of the shaft guide hole 16. The axial extent of each of these rectangles is greater than its radial extent. It has surprisingly been found that due to the projection 20 and especially due to the described rectangular shape, the material stress in the recess bottom is reduced, and this results in a longer service life of the brake caliper housing 5. This projection shape is suitable for use in combination with the embodiments of the present invention described above. However, this shape of the projection 20 can also be used independently of the features of the present invention described above to increase the service life.

[0051] This situation is similar to the pressure equalization through-hole 8, which is shown in the bottom 15 of the recess. When the brake piston 40 extends or retracts, the pressure can be equalized through this through-hole 8, and thus the material stress caused by air pressure is reduced or avoided. The through-hole 8 can be connected in an air-conducting manner to the electromechanical drive 105 adjacent to the brake piston assembly 1. This element can also be provided in combination with or independently of the embodiments of the present invention described above.

[0052] Figure 11 An exemplary embodiment of a motor vehicle disc brake 100 according to the present invention is shown. The brake caliper housing 5 of the brake piston assembly 1 is held in a conventional manner on the brake bracket 101 in a manner allowing axial movement. On the drive side 7, the brake piston assembly 1 or the brake caliper housing 5 is adjacent to an electromechanical drive 105 that actuates the brake piston assembly 1. The electromechanical drive 105 includes a transmission assembly 106 and an electric motor 107.

Claims

1. An electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100), the brake piston assembly comprising: A brake caliper housing (5), comprising a recess (10) defined by a recess bottom (15) and a recess wall (11) extending into the brake caliper housing (5), wherein the recess (10) has a recess opening (13) opposite the recess bottom (15), and wherein the recess bottom (15) has a shaft guide hole (16) and a first rolling bearing seat (25); A brake piston (40) is supported in the recess (10) for axial movement, the brake piston having an end wall with which the brake piston (40) protrudes from the recess opening (13) and / or can be moved out of the brake caliper housing (5) through the recess opening (13), wherein the brake piston (40) comprises a brake piston wall (42) which surrounds an interior space (48) and has an interior (43) facing the interior space (48), wherein at least one internal thread is formed in the interior (43), a drive screw (55) comprising: a threaded portion (56) having at least one external thread; a shaft (63) extending through the shaft guide hole (16); and a second rolling bearing seat (65) arranged in a transition region (60) from the shaft (63) to the threaded portion (56), wherein the at least one external thread is operatively connected to the at least one internal thread with respect to driving, so that the drive screw (55) and the brake piston (40) together act as a screw driver (73); and A rolling bearing (75) having a rolling element guide (80) and having a plurality of rolling elements (77), said rolling elements rolling on a first raceway (85) comprised by said rolling element guide (80) and on a second raceway (69) comprised by said second rolling bearing seat (65), wherein said rolling element guide (80) has a first support surface (92) by means of which said rolling element guide (80) is supported in the axial direction against a first contact surface (27) of said first rolling bearing seat (25), It is characterized in that the rolling element guide (80) has a second support surface (94), by means of which the rolling element guide (80) is supported in the radial direction against the second contact surface (28) of the first rolling bearing seat (25), and / or by means of the second support surface, the rolling element guide (80) is held in a shape-locked manner by the first rolling bearing seat (25) in the radial direction.

2. The electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to claim 1, wherein: The recess bottom (15) comprises a first surface portion (18) facing the recess (10) and a protrusion (20) extending into the recess (10), wherein the protrusion (20) comprises the first rolling bearing seat (25), and wherein the first rolling bearing seat (25) is closer to the recess opening (13) than the first surface portion (18).

3. The electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to claim 2, wherein: The protrusion (20) comprises a second surface portion (22) connecting the first surface portion (18) and the first contact surface (27) to each other, wherein the second surface portion (22) comprises the second contact surface (28), wherein the second contact surface (28) adjoins the first contact surface (27).

4. The electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to claim 3, wherein: The second surface portion (22) is cylindrical and has a first diameter, wherein the second contact surface (28) is cylindrical and has a second diameter, wherein the second diameter is smaller than the first diameter.

5. The electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to claim 2, wherein: The first rolling bearing seat (25) comprises an annular flange (30) having a flange inner portion (31), a flange outer portion (32), and an end surface (33) connecting the flange inner portion (31) and the flange outer portion (32) and facing the recess opening (13). The area of ​​the first rolling bearing seat (25) not covered by the annular flange (30) includes the first contact surface (27), wherein the end surface (33) is closer to the recess opening (13) than the first contact surface (27).

6. The electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to claim 5, wherein: The first contact surface (27) is arranged outside the flange (30) in a radial direction, and wherein the flange outer portion (32) comprises the second contact surface (28).

7. The electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to claim 5, wherein: The first contact surface (27) is arranged inside the flange (30) in a radial direction, and wherein the flange interior (31) comprises the second contact surface (28).

8. An electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to any one of the preceding claims, wherein: The rolling element guide (80) is annular disc-shaped and includes a first circumferentially extending curved portion (86), wherein the first circumferentially extending curved portion (86) includes the second support surface (94).

9. The electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to claim 8, wherein: The first circumferentially extending curved portion (86) is located at the outer edge (81) of the rolling element guide (80) and faces away from the recess opening (13), wherein the second support surface (94) is located on the interior (43) of the first circumferentially extending curved portion (86), and / or wherein the rolling element guide (80) includes a second circumferentially extending curved portion (89) located at the inner edge (82) of the rolling element guide (80), wherein the second circumferentially extending curved portion (89) points toward the recess opening (13), wherein, in particular, the second circumferentially extending curved portion (89) guides at least a portion of the rolling element (77) in the radial direction.

10. The electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to claim 8, wherein: The first circumferentially extending curved portion (86) is located at the outer edge (81) of the rolling element guide (80) and points to the recess opening (13), wherein the second support surface (94) is located on the outside (88) of the first circumferentially extending curved portion (86), and / or wherein the rolling element guide (80) includes a second circumferentially extending curved portion (89) located at the inner edge (82) of the rolling element guide (80), wherein the second circumferentially extending curved portion (89) points to the recess opening (13), wherein, in particular, the second circumferentially extending curved portion (89) guides at least a portion of the rolling element (77) in the radial direction.

11. The electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to claim 8, wherein: The first circumferentially extending curved portion (86) is located at the inner edge (82) of the rolling element guide (80) and points to the recess opening (13), wherein the second support surface (94) is located on the interior (43) of the first circumferentially extending curved portion (86), and / or wherein the rolling element guide (80) includes a second circumferentially extending curved portion (89) located at the outer edge (81) of the rolling element guide (80), wherein the second circumferentially extending curved portion (89) points to the recess opening (13), wherein, in particular, the second circumferentially extending curved portion (89) guides at least a portion of the rolling element (77) in the radial direction.

12. An electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to any one of the preceding claims, wherein: The rolling bearing (75) is an axial rolling bearing, in particular a needle roller bearing.

13. An electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to any one of the preceding claims, wherein: The second rolling bearing seat (65) includes a bearing ring (67) and a third contact surface (61) located between the threaded portion (56) and the shaft (63), wherein the bearing ring (67) includes the second raceway (69) and a second support surface (94) opposite to the second raceway (69), wherein the second support surface (94) of the bearing ring (67) is axially supported against the third contact surface (61) directly or via a compensation ring (70).

14. An electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to any one of claims 2 to 13, wherein: The protrusion (20) is integrally joined to the caliper housing (5), and wherein the caliper housing (5) is a cast component.

15. An electromechanically actuatable brake piston assembly (1) for a motor vehicle brake (100) according to any one of the preceding claims, wherein: The at least one internal thread is in the form of an inner raceway (44), and the at least one external thread is in the form of an outer raceway (57), wherein the electromechanically actuatable brake piston assembly (1) includes a plurality of balls (58) that roll along the inner raceway (44) and the outer raceway (57), so that the drive screw (55) and the brake piston (40) together act as a ball screw drive (73).

16. A motor vehicle disc brake (100), comprising a brake support (101), an electromechanical drive (105) and a brake piston assembly (1) according to any one of claims 1 to 15, wherein the electromechanical drive has a transmission assembly (106) and an electric motor (107), and the brake piston assembly can be actuated by the electromechanical drive (105).

Images