Actuating device for master brake cylinder, assembly for hydraulic brake system

Abstract

The invention relates to an actuating device (4) for a master brake cylinder (2), the actuating device (4) having a transmission (19) and an electric motor (9) for driving the transmission (19), the transmission (19) having a spindle transmission (20) with a threaded spindle (22) and a spindle nut (21), the threaded spindle (22) or the spindle nut (21) being displaceable by the electric motor (9) in order to actuate the master brake cylinder (2), and the spindle transmission (20) being displaceable by the electric motor (9) in order to actuate the master brake cylinder (2). According to the invention, a threaded spindle (22), which can be moved by means of the electric motor (9), or a spindle nut (21), which can be moved by means of the electric motor (9), is equipped with a spring element (41), which applies a restoring force to the threaded spindle (22) or the spindle nut (21), which restoring force counteracts the actuation of the master brake cylinder (2). According to the invention, the spring element (41) is held in a preloaded manner between the threaded spindle (22) and the spindle nut (21), and the threaded spindle (22) and / or the spindle nut (21) can be rotated relative to the spring element (41).

Description

Technical Field

[0001] The present invention relates to an actuating device for a master brake cylinder, wherein the actuating device comprises a transmission and an electric motor for driving the transmission, wherein the transmission comprises a spindle transmission with a threaded spindle and a spindle nut, wherein the threaded spindle or the spindle nut can be moved by the electric motor to actuate the master brake cylinder, and wherein the threaded spindle or the spindle nut that can be moved by the electric motor is equipped with a spring element, which applies a restoring force to the threaded spindle or the spindle nut, which restoring force resists the actuation of the master brake cylinder.

[0002] Furthermore, the invention relates to an assembly for a hydraulic brake system, comprising an actuable master brake cylinder and an actuating device for actuating the master brake cylinder. Background Art

[0003] Hydraulic brake systems in motor vehicles typically have multiple friction brake devices hydraulically connected to the brake system's master brake cylinder. When the master brake cylinder is actuated, hydraulic fluid is transferred from the master brake cylinder to the slave cylinders of the friction brake devices, causing them to generate a friction braking torque. An actuating device is typically provided to actuate the master brake cylinder. With the increasing electrification of motor vehicles, the actuating devices of the brake system are also becoming increasingly electrified. To this end, the actuating device includes a transmission and an electric motor for driving the transmission. The transmission typically includes a spindle drive with a threaded spindle and a spindle nut. The threaded spindle and the spindle nut are moved by the electric motor to actuate the master brake cylinder.

[0004] An unpublished patent application by the applicant describes an actuating device in which a threaded spindle can be moved by an electric motor. To ensure that the moved threaded spindle can be reset even in the event of a motor failure, the threaded spindle is equipped with a spring element that applies a restoring force to the threaded spindle, which resists actuation of the master brake cylinder. This restoring force pushes the threaded spindle away from the master brake cylinder. The spring element is preloaded between the threaded spindle and a support cap fixed relative to the housing. To compensate for radial misalignment between the threaded spindle and the support cap, the spring element is conically shaped. Summary of the Invention

[0005] The actuating device according to the present invention, having the features of claim 1, has the advantage that the load on the electric motor and transmission can be reduced compared to known actuating devices. To this end, the present invention provides that a spring element is held preloaded between the threaded spindle and the spindle nut, and that the threaded spindle and / or the spindle nut are rotatable relative to the spring element. Conically extending spring elements typically have a nonlinear spring characteristic curve. Conversely, the provided restoring force increases disproportionately, i.e., excessively, with compression of the spring element. Consequently, the use of conically extending spring elements in actuating devices for master brake cylinders can lead to increased loads on the electric motor and transmission. Since the spring element is held preloaded between the threaded spindle and the spindle nut according to the present invention, a conically extending spring element is not necessary. At most, a minor radial offset between the threaded spindle and the spindle nut must be compensated. In a spindle drive, the threaded spindle and the spindle nut are rotatable relative to each other. When the terms "axial" and "radial" are used within the scope of this disclosure, unless expressly stated otherwise, these terms refer to the axis of rotation of the rotatably mounted transmission element of the spindle drive. To prevent the spring element from being subjected to torque due to rotation of the rotatably supported transmission element of the screw drive (i.e., the lead screw nut or threaded spindle), the threaded spindle and / or lead screw nut are rotatable relative to the spring element. Specifically, only the threaded spindle is rotatable relative to the spring element. Therefore, the first end of the spring element, associated with the threaded spindle, is rotatably supported on the threaded spindle. The second end of the spring element, associated with the lead screw nut, is non-rotatably connected to the lead screw nut. Alternatively, only the lead screw nut is rotatable relative to the spring element. The second end of the spring element is rotatably supported on the lead screw nut. The first end of the spring element is non-rotatably connected to the threaded spindle. Alternatively, both the lead screw nut and the threaded spindle can rotate relative to the spring element. As previously mentioned, both the threaded spindle and the lead screw nut are movable by an electric motor. Preferably, the threaded spindle is movable by an electric motor. The spring element is arranged so that it applies a restoring force to the threaded spindle, which resists manipulation of the master brake cylinder. Consequently, this restoring force pushes the threaded spindle away from the master brake cylinder. Since, according to the present invention, the spring element is held preloaded between the threaded spindle and the spindle nut, the spring element thus applies a force on the spindle nut that is directed opposite to the restoring force. Alternatively, the spindle nut can preferably be moved by an electric motor. The spring element is then arranged such that it applies a restoring force on the spindle nut that counteracts actuation of the master brake cylinder. Since, according to the present invention, the spring element is held preloaded between the threaded spindle and the spindle nut, the spring element thus applies a force on the spindle that is directed opposite to the restoring force.

[0006] According to a preferred embodiment, the spring element is cylindrical. Cylindrical spring elements generally have a linear spring characteristic curve, which is associated with low loads on the electric motor and transmission. According to an alternative embodiment, the spring element is conically extended, wherein the opening angle of the conically extended spring element is preferably less than 10°.

[0007] Preferably, the spring element is a helical spring. Such spring elements are available at a low cost. Particularly preferably, the threaded spindle and the spring element are arranged concentrically relative to each other.

[0008] According to a preferred embodiment, the threaded spindle has a first end facing away from the master brake cylinder, and the spring element applies a restoring force to the first end of the threaded spindle. In this embodiment, the threaded spindle can be moved by an electric motor. The first end of the threaded spindle is easily accessible for the arrangement of the spring element, making this embodiment of the actuating device structurally simple to implement.

[0009] According to a preferred embodiment, a sleeve is arranged at the first end of the threaded screw, which sleeve protrudes axially beyond the first end of the threaded screw, and the first end of the spring element associated with the threaded screw is arranged at the axial stop of the sleeve. Therefore, the first end of the spring element is not arranged directly at the threaded screw, but at the sleeve. A structure that is particularly suitable for arranging the first end of the spring element can be provided by the sleeve. Preferably, the sleeve has a radial protrusion protruding radially outward, which forms an axial stop for the first end of the spring element. The radial protrusion can compensate for any radial offset between the threaded screw and the screw nut. According to an alternative embodiment, it is preferably provided that the first end of the spring element is arranged directly at the threaded screw.

[0010] Preferably, the sleeve is rotatably supported on the threaded spindle. Thus, at least the threaded spindle is rotatable relative to the spring element. Since the first end of the threaded spindle is easily accessible as described above, the rotatable support of the sleeve on the threaded spindle can be realized in a structurally simple manner. Since the radial extension of the threaded spindle is relatively small, the support of the sleeve on the threaded spindle can also be realized cost-effectively. Preferably, the sleeve is rotatably supported on the threaded spindle by a rotary bearing having a plurality of rolling elements. However, the sleeve can also be rotatably supported on the threaded spindle by a sliding bearing.

[0011] According to a preferred embodiment, the sleeve is axially secured to the threaded spindle by a retaining ring inserted into the threaded spindle. The retaining ring preferably radially engages in a radially outwardly open circumferential groove of the threaded spindle to secure the sleeve. The retaining ring preferably cooperates with the aforementioned rolling elements of the rotary bearing to secure the sleeve. Alternatively, the retaining ring can directly cooperate with the sleeve to secure it.

[0012] According to a preferred embodiment, the second end of the spring element, which is associated with the spindle nut, is arranged at an axial stop of the spindle nut, axially opposite the axial stop of the sleeve. Since the two axial stops are axially opposite each other, a cylindrical spring element, in particular a cylindrical helical spring, can be used. Here, the second end of the spring element directly abuts the spindle nut, i.e., the axial stop. According to an alternative embodiment, the second end abuts the spindle nut only indirectly, for example, against an element rotatably mounted on the spindle nut.

[0013] According to a preferred embodiment, the spindle nut has a first axial section facing the master brake cylinder and a second axial section facing away from the master brake cylinder, wherein the first axial section has internal teeth associated with the threaded spindle, and wherein the second axial section at least partially radially surrounds the spring element. Since the second axial section radially surrounds the spring element, the second axial section prevents bending of the spring element during operation. Preferably, a circumferential stop step is formed at the transition between the first axial section and the second axial section, wherein the stop step forms an axial stop at which the second end of the spring element is arranged.

[0014] Preferably, the actuating device includes a pressure piston that is displaceably mounted in an axial opening of the threaded spindle and can be moved via an input rod, wherein the master brake cylinder can be actuated by moving the pressure piston. The pressure piston can then also be moved via the input rod. The input rod is coupled or can be coupled to the brake pedal, so that the pressure piston can ultimately be moved by actuating the brake pedal. Since the master brake cylinder can be actuated by moving the pressure piston, the user can still actuate the master brake cylinder even if the electric motor fails.

[0015] Preferably, the actuating device includes a further spring element that applies a restoring force to the threaded spindle and the pressure piston, which resists actuation of the master brake cylinder. In this embodiment, the threaded spindle is a transmission element of the spindle drive that can be moved by the electric motor. Therefore, in addition to the spring element, a further spring element is also present. Both the threaded spindle and the pressure piston can be reset by the further spring element. Providing a spring element and a further spring element instead of a single spring element that applies a restoring force to the transmission element and the pressure piston has the advantage of enabling different restoring forces to be achieved for the transmission element and the pressure piston. By way of example only, the restoring force acting on the pressure piston should not exceed 200N. However, this restoring force may not be sufficient to reset the threaded spindle in the event of a failure of the electric motor. By prestressing the spring element between the threaded spindle and the spindle nut, the restoring force acting on the threaded spindle can be increased without also increasing the restoring force acting on the pressure piston.

[0016] According to a preferred embodiment, the threaded spindle and the spindle nut are mechanically coupled to a pressure piston so that, at least in the event of a failure of the electric motor, the threaded spindle and the spindle nut can be moved together by moving the pressure piston. For example, the pressure piston is designed to transmit forces acting in the direction of the master brake cylinder to the threaded spindle as a function of its movement. The external teeth of the threaded spindle also mesh with the internal teeth of the spindle nut, so that forces are also transmitted via the threaded spindle to the spindle nut. Since the threaded spindle and the spindle nut can be moved together or moved in the event of a failure of the electric motor, the spring element, which is prestressed between the threaded spindle and the spindle nut, does not become compressed. Accordingly, in the event of a failure of the electric motor, the user of the brake pedal does not need to overcome the restoring force provided by the spring element.

[0017] According to a preferred embodiment, the transmission comprises a worm wheel that radially surrounds the spindle nut, wherein the radially inward-pointing multi-tooth profile of the worm wheel meshes with the radially outward-pointing multi-tooth profile of the spindle nut. During fault-free operation of the electric motor, a reaction force acting between the multi-tooth profiles prevents axial movement of the spindle nut. If the electric motor fails, this reaction force disappears, allowing the spindle nut and the threaded spindle to move together.

[0018] The multi-tooth profile of the spindle nut is preferably formed at least partially on the second axial section of the spindle nut. This has the advantage that the two multi-tooth profiles remain in mutual engagement even when the spindle nut is displaced in the axial direction. The multi-tooth profile of the spindle nut preferably extends to the end of the second axial section facing away from the master brake cylinder.

[0019] The assembly according to the invention having the features of claim 15 is characterized by an actuating device designed according to the invention. This also leads to the advantages described above. Further preferred features and feature combinations can be derived from the above description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be described in more detail below with reference to the accompanying drawings, wherein:

[0021] Figure 1 The components of the hydraulic brake system are shown;

[0022] Figure 2 A cross-sectional view of the assembly is shown;

[0023] Figure 3 Another cross-sectional view of the assembly is shown. DETAILED DESCRIPTION

[0024] Figure 1 The present invention shows a perspective view of an assembly 1 for a hydraulic brake system (not shown in detail) of a motor vehicle. The assembly 1 has an actuable master brake cylinder 2 having a plurality of hydraulic connections 3 . Figure 1Two hydraulic pistons 13, not visible in the figure, are movably mounted in the master brake cylinder 2. If the assembly 1 is installed as intended in the brake system, the hydraulic connection 3 is fluidically connected to the slave cylinders of the friction brake devices of the brake system, so that the friction brake devices can be actuated by actuating the master brake cylinder 2.

[0025] The assembly 1 also has an actuating device 4 for actuating the master brake cylinder 2. The actuating device 4 has a housing 5. The master brake cylinder 2 is arranged on a first end side 12 of the housing 5. In the present case, the housing 5 is tubular and therefore has a circumferential side wall 6 which surrounds a housing interior 7 of the housing 5. The actuating device 4 also has a drive unit 8 which is arranged on the housing 5. The drive unit 8 has an electric motor 9 which is arranged in a motor housing 10 and thus Figure 1 The operating device 4 further comprises a control unit 11 . The control unit 11 is arranged on the housing 5 on a side of the housing 5 facing away from the drive unit 8 . The control unit 11 is designed to actuate the electric motor 9 .

[0026] Additional references below Figure 2 and Figure 3 The design of the operating device 4 is explained in more detail. Figure 2 A cross-sectional view of the assembly 1 is shown. Figure 3 A sectional view of a portion of an actuating device 4 is shown. The actuating device 4 has a movable coupling element 14. In the present case, the coupling element 14 comprises an elastically deformable coupling disc 15 and a rigid coupling rod 16. The coupling element 14 is movable in a first direction 17 and in a second direction 18 opposite to the first direction 17. The coupling element 14 is operatively connected or can be operatively connected to the master brake cylinder 2, so that the master brake cylinder 2 can be actuated by moving the coupling element 14 in the first direction 17. Actuating the master brake cylinder 2 is to be understood as moving the hydraulic piston 13 in the first direction 17. If the assembly 1 is installed correctly in the brake system, hydraulic fluid is thus displaced from the master brake cylinder 2 into the slave cylinders of the wheel brake systems.

[0027] The actuating device 4 also has a transmission 19. The transmission 19 is operatively connected to the electric motor 9 so that the transmission 19 can be driven by the electric motor 9. The transmission 19 has a spindle drive 20. The spindle drive 20 has a spindle nut 21 and a threaded spindle 22. In the present case, the spindle nut 21 is rotatably mounted. The axis of rotation 24 of the spindle nut 21 is oriented parallel to the directions 17 and 18. The threaded spindle 22 is equipped with a rotation prevention device 25, which acts between the threaded spindle 22 and the housing 5. For this purpose, an anti-rotation element 26 is provided. This anti-rotation element is fixed to the threaded spindle 22, in the present case, at the end of the threaded spindle 22 facing the coupling element 14 or the master brake cylinder 2. The anti-rotation element 26 cooperates with the housing 5 to form the anti-rotation device 25. The internal teeth 27 of the spindle nut 21 mesh with the external teeth 28 of the threaded spindle 22, so that the threaded spindle 22 can be moved by rotating the spindle nut 21, that is, selectively in the first direction 17 or the second direction 18. The threaded spindle 22 is operatively connected to the coupling element 14, so that the coupling element 14 can be moved by moving the threaded spindle 22 in the first direction 17. In the present case, a thrust member 29 is fixed to the anti-rotation element 26. The thrust member 29 protrudes from the anti-rotation element 26 in the direction of the coupling element 14, so that the thrust member 29 rests axially against the coupling element 14 relative to the axis of rotation 24 of the spindle nut 21.

[0028] The spindle nut 21 can be rotated by the electric motor 9. Accordingly, the threaded spindle 22 can be moved by the electric motor 9. To this end, the transmission 19 in the present case includes a worm wheel 30 that radially surrounds the spindle nut 21. The radially inward-pointing multi-tooth profile 31 of the worm wheel 30 meshes with the radially outward-pointing multi-tooth profile 32 of the spindle nut 21. The transmission 19 also includes a worm shaft 33 that can be rotated by the electric motor 9. The driven teeth of the worm shaft 33 mesh with the driving teeth of the worm wheel 30, so that the worm wheel 30, and therefore the spindle nut 21, can be rotated by rotating the worm shaft 33.

[0029] The operating device 4 also has a pressure piston 34 that is supported so as to be movable relative to the threaded spindle 22. The pressure piston 34 is supported so as to be movable in an axial opening 35 of the threaded spindle 22. The first end 36 of the pressure piston 34 that faces away from the master brake cylinder 2 or the coupling element 14 is operatively connected to an input rod 38 via a ball joint 37, so that the pressure piston 34 can be moved by the input rod 38. The input rod 38 is in turn coupled to or can be coupled to a brake pedal of the braking system. If the input rod 38 is coupled to the brake pedal, the pressure piston 34 can be moved by the brake pedal. A pressure cap 40 is fixed to the second end 39 of the pressure piston 34 that faces the coupling element 14. The pressure cap 40 protrudes into the axial opening 57 of the pusher 29 so that the end side 58 of the pressure cap 40 can come into contact with the coupling element 14. Therefore, the coupling element 14 can also be moved by the movement of the pressure piston 34, so that the master brake cylinder 2 can be actuated by moving the pressure piston 34. Figure 2 In the basic position of the actuating device 4 shown, the pressure cap 40 is axially spaced apart from the coupling element 14 .

[0030] Therefore, the coupling element 14 can be moved both by the electric motor 9 and by the brake pedal. If the coupling element 14 is moved by the electric motor 9, the electric motor 9 acts on the coupling element 14 via the transmission 19, the anti-rotation element 26, and the pusher 29. If the coupling element 14 is moved by the brake pedal, the brake pedal acts on the coupling element 14 via the input rod 38, the pressure piston 34, and the pressure cap 40.

[0031] The actuating device 4 further includes a spring element 41. The spring element 41 is configured to exert a restoring force on the threaded spindle 22, which is movable by the electric motor 9, that resists actuation of the master brake cylinder 2. Consequently, the restoring force acts on the threaded spindle 22 in the second direction 18, pushing the threaded spindle 22 away from the master brake cylinder. After actuation of the master brake cylinder 2, the threaded spindle 22 is reset by the spring element 41. The spring element 41 is held prestressed between the threaded spindle 22 and the spindle nut 21. Accordingly, the spring element 41 exerts a force on the spindle nut 21 that acts in the direction of the master brake cylinder 2, that is, in the first direction 17.

[0032] The actuating device 4 includes a sleeve 42, which is arranged at a first end 43 of the threaded spindle 22 facing away from the master brake cylinder 2. The sleeve 42 is pushed onto the threaded spindle 22 and is rotatably supported thereon. For this purpose, a rotary bearing 45 with a plurality of rolling elements 44 is provided, which acts between the sleeve 42 and the threaded spindle 22. The sleeve 42 is axially fixed to the threaded spindle 22 by a retaining ring 46. The retaining ring 46 is inserted into the threaded spindle 22 and radially engages in a radially outwardly open circumferential groove 47 of the threaded spindle 22. The first end 48 of the spring element 41, which is associated with the threaded spindle 22, is arranged at an axial stop 49 of the sleeve 42. The axial stop 49 is formed by a radial projection 50 of the sleeve 42 that protrudes radially outward. The spring element 41 exerts a restoring force on the threaded spindle 22, more specifically, on the first end 43 of the threaded spindle 22, via the sleeve 42. Since the spring element 41 is not arranged directly on the threaded spindle 22, but on the sleeve 42, the threaded spindle 22 and the spring element 41 can rotate relative to each other. In this regard, the rotation of the spindle nut 21 relative to the threaded spindle 22 is not hindered by the spring element 41, or at most only slightly hindered.

[0033] The second end 51 of the spring element 41, which is associated with the spindle nut 21, is arranged at an axial stop 52 of the spindle nut 21, which is axially opposite the axial stop 49 of the sleeve 42. Since the axial stops 49 and 52 are axially opposite each other, a cylindrical spring element 41 can be used as the spring element 41. A cylindrical spring element 41 is particularly advantageous for this purpose because it has a linear spring characteristic curve. In the present case, the spring element 41 is designed as a coil spring 41.

[0034] The spindle nut 21 has a first axial section 53 facing the master brake cylinder 2 and a second axial section 54 facing away from the master brake cylinder 2. The first axial section 53 has internal teeth 27. The second axial section 54 does not have internal teeth 27. The second axial section 54 at least partially surrounds the spring element 41. The aforementioned radially outwardly pointing multi-tooth profile 32 is formed on the first axial section 53 and the second axial section 54. In the present case, the multi-tooth profile 32 extends from the end of the spindle nut 21 facing the master brake cylinder 2 to the end of the spindle nut 21 facing away from the master brake cylinder 2.

[0035] The actuating device 4 further comprises a further spring element 55. The further spring element 55 is held in a prestressed manner between a restoring body 56 fixed to the coupling element 14 and the master brake cylinder 2. Accordingly, the further spring element 55 exerts a restoring force acting in the second direction 18 on the coupling element 14 and thus on the threaded spindle 22 and the pressure rod 34.

[0036] The function of the actuating device 4 will be explained in more detail below. During trouble-free operation of the electric motor 9, the electric motor 9 is actuated based on the detected sliding position of the pressure piston 34. If the pressure piston 34 moves in the first direction 17, the electric motor 9 is actuated to move the threaded spindle 22 in the first direction 17, thereby actuating the master brake cylinder 2. The threaded spindle 22 moves in the first direction 17 against the restoring force provided by the spring element 41 and the further spring element 55. After actuating the master brake cylinder 2, the threaded spindle 22 is reset by the restoring force provided by the spring elements 41 and 55. The pressure piston 34 is reset solely by the restoring force provided by the further spring element 55. However, the restoring force provided by the spring element 41 does not act on the pressure piston 34. If the electric motor 9 fails, the threaded spindle 22 cannot be moved in the first direction 17 by the electric motor 9. However, the master brake cylinder 2 can still be actuated by moving the pressure piston 34. To do this, the user only needs to overcome the restoring force provided by the further spring element 55. If the coupling element 14 is moved in the first direction via the pressure rod 34, a force acting in the first direction 17 also acts on the threaded spindle 22 due to the mechanical operative connection between the coupling element 14 and the threaded spindle 22. This force causes the threaded spindle 22 and the spindle nut 21 to move together with the pressure piston 34. In this case, the spring element 41 does not compress. Due to the size of the radially outward-pointing multi-tooth profile 32 of the spindle nut 21, the multi-tooth profiles 31 and 32 are prevented from disengaging when the spindle nut 21 is moved. During trouble-free operation of the electric motor 9, the reaction force acting between the multi-tooth profiles 31 and 32 prevents the spindle nut 21 from moving.

[0037] According to another embodiment, the spindle nut 21 can be moved by the electric motor 9 instead of the threaded spindle 22 . In this case, the spring element 41 applies a restoring force acting in the second direction 18 to the spindle nut 21 .

Claims

1. An actuating device for a master brake cylinder, wherein: The operating device (4) has a transmission (19) and an electric motor (9) for driving the transmission (19), wherein the transmission (19) has a spindle transmission (20) with a threaded spindle (22) and a spindle nut (21), wherein the threaded spindle (22) or the spindle nut (21) can be moved by the electric motor (9) to operate the master brake cylinder (2), and wherein the threaded spindle (22) that can be moved by the electric motor (9) or the spindle nut (21) can be moved by the electric motor (9) to operate the master brake cylinder (2). The spindle nut (21) moved by the electric motor (9) is equipped with a spring element (41), which applies a restoring force to the threaded spindle (22) or the spindle nut (21), and the restoring force resists the operation of the master brake cylinder (2), characterized in that the spring element (41) is held preloaded between the threaded spindle (22) and the spindle nut (21), and the threaded spindle (22) and / or the spindle nut (21) can rotate relative to the spring element (41).

2. The operating device according to claim 1, characterized in that The spring element (41) is cylindrical in shape.

3. An operating device according to any one of the preceding claims, characterized in that The spring element (41) is a coil spring (41).

4. An operating device according to any one of the preceding claims, characterized in that The threaded spindle (22) has a first end (43) facing away from the master brake cylinder (2), and the spring element (41) applies the restoring force to the first end (43) of the threaded spindle (22).

5. The operating device according to claim 4, characterized in that A sleeve (42) is arranged at the first end (43) of the threaded spindle (22), which sleeve protrudes axially beyond the first end (43) of the threaded spindle (22), and the first end of the spring element (41) associated with the threaded spindle (22) is arranged at an axial stop (49) of the sleeve (42).

6. The operating device according to claim 5, characterized in that The sleeve (42) is rotatably supported on the threaded spindle (22).

7. The operating device according to claim 6, characterized in that The sleeve (42) is axially fixed on the threaded screw (22) by means of a clamping ring (46) plugged into the threaded screw (22).

8. The operating device according to any one of claims 5 to 7, characterized in that A second end (51) of the spring element (41) associated with the spindle nut (21) is arranged on an axial stop (52) of the spindle nut (22) axially opposite an axial stop (49) of the sleeve (42).

9. An operating device according to any one of the preceding claims, characterized in that The spindle nut (22) has a first axial section (53) facing the master brake cylinder (2) and a second axial section (54) facing away from the master brake cylinder (2), wherein the first axial section (53) has an internal toothing (27) associated with the threaded spindle (22), and wherein the second axial section (54) at least partially radially surrounds the spring element (41).

10. An operating device according to any one of the preceding claims, characterized in that The actuating device (4) has a pressure piston (34) which is displaceably mounted in an axial opening (35) of the threaded spindle (22) and can be moved via an input rod (38), wherein the master brake cylinder (2) can be actuated by moving the pressure piston (34).

11. The operating device according to claim 10, characterized in that A further spring element (55) is also provided, which exerts a restoring force on the threaded spindle (22) and the pressure piston (34), said restoring force counteracting an actuation of the master brake cylinder (2).

12. The operating device according to claim 11, characterized in that The threaded spindle (22) and the spindle nut (21) are mechanically coupled to the pressure piston (34) so ​​that, at least in the event of a failure of the electric motor (9), the threaded spindle (22) and the spindle nut (21) can be moved together by moving the pressure piston (34).

13. An operating device according to any one of the preceding claims, characterized in that The transmission (19) has a worm wheel (30) which radially surrounds the spindle nut (21), wherein a radially inwardly directed multi-tooth profile (31) of the worm wheel (30) meshes with a radially outwardly directed multi-tooth profile (32) of the spindle nut (21).

14. The operating device according to claim 13, characterized in that The multi-tooth profile (32) of the spindle nut (21) is formed at least partially on a second axial section (54) of the spindle nut (21).

15. A component for a hydraulic brake system, comprising an actuable master brake cylinder (2) and an actuating device (4) for actuating the master brake cylinder (2), characterized in that: The actuating device (4) has a design according to any of the preceding claims.

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