Abstract
An adjustment unit, particularly for use in a commercial vehicle brake, comprising a stator and a rotor, wherein the stator and/or rotor have a coil arrangement, wherein the rotor is mounted in such a way that it can rotate about an actuation axis relative to the stator, and the stator is secured in such a way that it cannot rotate about the actuation axis relative to a main body, wherein it is possible to generate, in the coil arrangement, a magnetic field which rotates the rotor relative to the stator, wherein the rotor is in engagement with a first transmission section in such a way that a rotation of the rotor results in shifting of the first transmission section relative to the stator along the actuation axis.
Claims
1.-15. (canceled)
16. A brake adjustment unit, comprising: a stator; and a rotor; wherein at least one of the stator and the rotor have a coil arrangement; wherein the rotor is mounted to rotate about an actuation axis relative to the stator, and the stator is secured to prevent rotation about the actuation axis relative to a main body; wherein the coil arrangement is configured to generate a magnetic field which rotates the rotor relative to the stator; wherein the rotor is in engagement with a first transmission section such that a rotation of the rotor results in shifting of the first transmission section relative to the stator along the actuation axis; wherein the stator has a second transmission section, wherein an actuating force of an actuating unit acting along the actuation axis can be received at at least one of the first transmission section and the second transmission section and transmitted in the other of the first transmission section and the second transmission section to a shoe element.
17. The brake adjustment unit as claimed in claim 16, wherein the stator and the rotor are arranged at least partially within a space defined by the main body.
18. The brake adjustment unit as claimed in claim 17, wherein the stator and the rotor are arranged predominantly within the space defined by the main body.
19. The brake adjustment unit as claimed in claim 17, wherein the rotor is arranged predominantly within a space defined by the stator.
20. The brake adjustment unit as claimed in claim 19, wherein the rotor has a permanent magnet.
21. The brake adjustment unit as claimed in claim 20, wherein the rotor is secured against shifting along the actuation axis relative to the stator.
22. The brake adjustment unit as claimed in claim 21, wherein the stator and the rotor, together with at least one of the coil arrangement and a permanent magnet, and two coil arrangements, form a stepper motor, and wherein the coil arrangement has at least four windings distributed around the actuation axis.
23. The brake adjustment unit as claimed in claim 22, wherein the first transmission section is part of an actuation element, and wherein the actuation element is mounted such that the actuation element can rotate relative to the rotor and is in engagement with the rotor via a thread.
24. The brake adjustment unit as claimed in claim 23, wherein rotation of the rotor about the actuation axis relative to the actuation element brings about a change in the extent of the composite structure comprising the actuation element, the rotor and the stator along the actuation axis.
25. The brake adjustment unit as claimed in claim 24, wherein the actuation element has a securing section which is in engagement with at least one of a main-body anti-rotation safeguard and a shoe anti-rotation safeguard configured to secure the actuation element against rotation about the actuation axis relative to at least one of the main body and the shoe element.
26. The brake adjustment unit as claimed in claim 25, wherein the actuation element comprises an actuation bolt that includes an external thread which engages an internal thread on a rotor recess of the rotor.
27. The brake adjustment unit as claimed in claim 25, wherein the actuation element comprises an actuation recess having an internal thread, in which an external thread of a rotor bolt of the rotor engages.
28. The brake adjustment unit as claimed in claim 11, wherein the coil arrangement at least partially surrounds the rotor and has a mean coil diameter, wherein the engagement region between the rotor and the actuation element has a mean engagement diameter, and wherein the mean engagement diameter is at most 0.8 times the mean coil diameter.
29. The brake adjustment unit as claimed in claim 28, wherein the mean engagement diameter is at most 0.6 times the mean coil diameter.
30. The brake adjustment unit as claimed in claim 29, wherein the mean engagement diameter is between about 0.3 and about 0.5 times the mean coil diameter.
31. The brake adjustment unit as claimed in claim 28, wherein the main body is part of at least one of a housing of a wedge brake and of a brake caliper, and wherein the main body has an opening through which a cable for supplying power to the coil arrangement can be passed.
32. The brake adjustment unit as claimed in claim 31, wherein a self-locking thread is provided at least one of between the actuation element and the rotor and between the stator and the rotor.
33. The brake adjustment unit as claimed in claim 16, wherein the rotor is arranged predominantly within a space defined by the stator.
34. The brake adjustment unit as claimed in claim 16, wherein the rotor has a permanent magnet.
35. The brake adjustment unit as claimed in claim 16, wherein the rotor is secured against shifting along the actuation axis relative to the stator.
36. The brake adjustment unit as claimed in claim 16, wherein the stator and the rotor, together with at least one of the coil arrangement and a permanent magnet, and two coil arrangements, form a stepper motor, and wherein the coil arrangement has at least four windings distributed around the actuation axis.
37. The brake adjustment unit as claimed in claim 16, wherein the first transmission section is part of an actuation element, and wherein the actuation element is mounted such that the actuation element can rotate relative to the rotor and is in engagement with the rotor via a thread.
38. The brake adjustment unit as claimed in claim 37, wherein rotation of the rotor about the actuation axis relative to the actuation element brings about a change in the extent of the composite structure comprising the actuation element, the rotor and the stator along the actuation axis.
39. The brake adjustment unit as claimed in claim 37, wherein the actuation element has a securing section which is in engagement with at least one of a main-body anti-rotation safeguard and a shoe anti-rotation safeguard configured to secure the actuation element against rotation about the actuation axis relative to at least one of the main body and the shoe element.
40. The brake adjustment unit as claimed in claim 37, wherein the actuation element comprises an actuation bolt that includes an external thread which engages an internal thread on a rotor recess of the rotor.
41. The brake adjustment unit as claimed in claim 37, wherein the actuation element comprises an actuation recess having an internal thread, in which an external thread of a rotor bolt of the rotor engages.
42. The brake adjustment unit as claimed in claim 37, wherein the coil arrangement at least partially surrounds the rotor and has a mean coil diameter, wherein the engagement region between the rotor and the actuation element has a mean engagement diameter, and wherein the mean engagement diameter is at most 0.8 times the mean coil diameter.
43. The brake adjustment unit as claimed in claim 16, wherein the main body is part of at least one of a housing of a wedge brake and of a brake caliper, and wherein the main body has an opening through which a cable for supplying power to the coil arrangement can be passed.
44. The brake adjustment unit as claimed in claim 16, wherein a self-locking thread is provided at least one of between the actuation element and the rotor and between the stator and the rotor.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Further advantages and features of the present invention will become apparent from the following description with reference to the attached figures. It is self-evident that individual features respectively explained for just one embodiment described in the figures can also be used in other embodiments in other figures unless this has been explicitly excluded or is impossible owing to technical circumstances. In particular, it is possible here for the features explained in relation to an adjustment device without an actuation element also to be used in the embodiments with an actuation element and vice versa unless this is explicitly excluded or technically not worthwhile. In the drawing:
[0021] FIG. 1 shows a schematic view of a preferred embodiment of the adjustment unit according to the invention without actuation element;
[0022] FIG. 2 shows a view of the adjustment unit shown in FIG. 1 in the extended state;
[0023] FIG. 3 shows a schematic and partially sectioned view of two adjustment units in the sense according to the present invention for use in a wedge brake;
[0024] FIG. 4 shows a partially sectioned view of an alternative embodiment of the adjustment unit illustrated in FIG. 3;
[0025] FIG. 5 shows a partially sectioned view of an adjustment unit for use in a disk brake system; and
[0026] FIG. 6 shows a sectional view of an alternative embodiment of the adjustment unit illustrated in FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] FIG. 1 shows a first preferred embodiment of the adjustment unit according to the invention, in which a stator 2 is mounted in a recess in a main body 5 in such a way that it can be shifted along an actuation axis B. A rotor 4 is preferably arranged substantially within a recess in the stator 2, said rotor being supported on the stator via a thread. In this case, the rotor 4 has on its end face facing outward or to the left in the figure a first transmission section 9, via which a supporting force can be transmitted to a shoe element 8 along the actuation axis B. On the opposite side from the first transmission section 9, the composite structure comprising the stator 2 and the rotor 4 has a second transmission section 10, which in the present case is preferably designed as an oblique surface, which is capable of absorbing a force of an actuating unit 12. In the present example, the actuating unit 12 is preferably a wedge unit, which transmits a force to the stator 2 along the actuation axis B in order to press the composite structure comprising the stator 2 and the rotor 4 against the shoe element 8. In order to prevent rotation of the stator 2 within the opening of the main body 5, the stator 2 has a stator anti-rotation safeguard 25 or a securing section 65, which engages in a corresponding main-body anti-rotation safeguard 55 and allows the possibility of shifting along the actuation axis but, at the same time, prevents rotation of the stator 2 about the actuation axis B. On its inside, the stator 2 has a coil arrangement 7, which, in the present case, preferably consists of four windings 72. Arranged on the rotor is a permanent magnet 71, which is arranged in such a way that a magnetic field generated in the windings 72 generates a torque in the permanent magnet 71 about the actuation axis B. In this way, it is possible, by applying a voltage and by generating an electric current in the coil arrangement 7 or in the windings 72, to generate a magnetic field, which imparts rotation about the actuation axis B to the rotor 4 relative to the stator. During this rotation of the rotor 4, it is supported on a thread, via which it is fixed on the stator 2, wherein a shifting movement of the rotor 4 takes place parallel to the actuation axis B. In FIG. 1, the rotor 4 is illustrated in the position in which it is fully screwed into the stator 2. This position would be present if the brake shoe pads on the shoe element 8 had just been renewed and thus had no wear and adjustment of the rotor 4 in relation to the stator 2 was not yet necessary. The coil arrangement 7 has a mean coil diameter D.sub.7, which, in the present case, is only slightly larger than the mean engagement diameter D.sub.4 between the rotor 4 and the stator 2 in the thread connecting the two components. With the embodiment shown in FIG. 1, it is thus possible to achieve a particularly compact construction with an external geometry of the stator 2 which is substantially cylindrical (apart from the stator anti-rotation safeguard 25). As a particular preference, a friction-reducing material, which reduces the friction during rotation of the rotor 4 relative to the stator 2 and also relative to the shoe element 8, is provided in the first transmission section 9.
[0028] FIG. 2 shows the embodiment of the adjustment unit illustrated in FIG. 1, wherein the rotor 4 is illustrated in its position screwed out of the stator 2 to the maximum extent, this position being envisaged in operation. This position is thus preferably implemented in the adjustment unit when the brake shoe pads are almost completely worn away and should be replaced soon. FIGS. 1 and 2 also illustrate the fact that the permanent magnet 71, which is fixed on the rotor 4, has a smaller extent along the actuation axis B and shifts along the actuation axis relative to the coil arrangement 7 or to the windings 72 on the stator 2 during the process of unscrewing or screwing the rotor relative to the stator. One advantageous possibility in the embodiment of the adjustment unit shown in FIGS. 1 and 2 is to dispense with an additional actuation element 6 of the kind required in the embodiments described below. In FIGS. 1 and 2, the power supply to the coil arrangement 7 or the windings 72 is not shown but it is self-evident that a cable can, of course, be passed through the stator 2 and passed out of the adjustment unit via an opening 51 (not shown) in the main body 5.
[0029] FIG. 3 shows another preferred embodiment of the adjustment unit according to the invention, wherein at least one stator 2 is arranged in such a way that it can be shifted along the actuation axis B in a main body 5, which is preferably the housing of a wedge unit. In the embodiment under consideration, in contrast to the embodiments of the adjustment unit according to the invention which are illustrated in FIGS. 1 and 2, an actuation element 6 is provided, which engages on the rotor 4 via a thread and is shifted relative to the rotor and to the stator 2 along the actuation axis by a rotation about the actuation axis. The advantage of this embodiment is that the coil arrangement 7 provided on the rotor 4 and on the stator 2 does not undergo a relative shifting movement along the actuation axis B, as in FIGS. 1 and 2, but can always be held precisely opposite. In this way, the coil arrangement 7 can be optimized for a maximum torque with a small overall size. Also illustrated is the fact that the mean coil diameter D.sub.7 is larger than the mean engagement diameter. The ratio of the mean engagement diameter D.sub.4 to the mean coil diameter D.sub.7 is preferably about 0.5-0.6 since in this way a particularly high torque can be generated in the thread between the rotor 4 and the actuation element 6 and the overall size of the overall composite structure comprising the stator 2, the rotor 4 and the actuation element 6 can be kept particularly compact and small. In the embodiment shown in FIG. 3, the first transmission section 9 is not arranged on the rotor 4 but on the actuation element 6. As in the embodiments shown above, the second transmission section 10 is provided on the stator 2 and engages on an actuating unit 12. In the embodiment illustrated in FIG. 3, the rotor 4 has a rotor recess 43, in which a section of the actuation element 6 designed as an actuation bolt 62 with an external thread engages. In the case of the stator 2 (illustrated on the right in the figure, not in section), a terminal 74, which can be connected to a cable via an opening 51 designed as an elongate hole in the main body 5 in order to ensure the appropriate voltage for supplying the coil arrangement 7 with power, is illustrated schematically and turned through 90° about the actuation axis B. The opening 51 is preferably designed as an elongate hole in such a way that the shifting movement of the stator 2 along the actuation axis B during a braking process can be carried out together with the power cable which is connected to the terminal without it being sheared off in the region of the guide in the main body 5. In the region of the first transmission section 9, the actuation element 6 has a securing section 65, which is in engagement with the shoe anti-rotation safeguard 85 of a brake shoe 8. As an alternative or in addition to the engagement with the shoe anti-rotation safeguard 85, it is also possible to provide the engagement shown in FIG. 1 comprising a main-body anti-rotation safeguard 55 on the actuation element 6. For this purpose, the actuation element 6 preferably has, on the cylindrical outer surface thereof, a securing section 65 similar to the stator anti-rotation safeguard 25.
[0030] FIG. 4 shows an alternative embodiment of the composite structure comprising the stator 2, the rotor 4 and the actuation element 6, it being possible to use said embodiment in an adjustment unit in accordance with FIG. 3. In this case, the actuation element 6 has, instead of the actuation bolt 62, an actuation recess 63, which can be screwed on from outside via the rotor 4 and a rotor bolt 42 provided on the rotor. The stator 2 and the coil arrangement 7 provided on the stator 2 are arranged within a recess in the rotor 4. The advantage of this embodiment is that the actuation element 6 surrounds the rotor 4 and the stator 2 at least over a large area and thus protects them from external influences. A stator anti-rotation safeguard 25, by means of which the stator engages on an actuating unit 12 and is simultaneously secured against rotation about the actuation axis B, is furthermore illustrated in the region of the second transmission section 10. The rotor 4 and the stator 2 are preferably secured against shifting relative to one another along the actuation axis B. In the embodiment illustrated in FIG. 4, this is accomplished by means of a snap ring, which is seated in a corresponding groove in the region of the distal end of the stator 2, illustrated on the left in the figure. In this way, it is easily possible to preassemble the rotor 4 and the stator 2 as a drive unit for the adjustment unit in advance and then simply to screw the actuation element 6 onto the corresponding arrangement upon installation into a brake unit of a commercial vehicle. In the case of the embodiments illustrated in FIG. 3 and FIG. 4, the actuation element 6 preferably has a securing section 65 designed as a groove for engagement in a shoe anti-rotation safeguard 85 (see FIG. 3) in order to secure the actuation unit 6 against rotation relative to the shoe element 8 about the actuation axis B.
[0031] FIG. 5 shows a preferred embodiment of the adjustment unit for use in a disk brake system of a commercial vehicle. Here, the second transmission section 10 is not subjected to a force by a wedge unit, as in the embodiments shown above, but by an actuating unit 12, which in the present case comprises a lever, which is driven by a brake cylinder. In the embodiment shown in FIG. 5, the interaction of the elements—the actuation element 6, the rotor 4 and the stator 2—takes place in a manner similar to that in the embodiment shown in FIG. 4. In this embodiment, the shoe element 8 is preferably a brake pad of a disk brake system. In order to allow favorable force transmission from the actuating unit 12 to the stator 2, the second transmission unit 10 preferably has a concavely curved geometry.
[0032] FIG. 6 shows an alternative embodiment of the composite structure comprising the stator 2, the rotor 4 and the actuation element 6 for use in the embodiment shown in FIG. 5. Here, the actuation element 6 is equipped with an actuation bolt 62, which engages in a rotor recess 43 having an internal thread in the rotor 4. In contrast to the embodiment shown in FIG. 5 therefore, the mean engagement diameter D.sub.4 in the region of the thread between the rotor 4 and the actuation element 6 is smaller than the mean coil diameter D.sub.7 of the coil arrangement 7 provided between the stator 2 and the rotor 4. In the embodiment shown in FIG. 6, the coil arrangement 7 thus generates a higher torque in the thread between the actuation element 6 and the rotor 4 than that in FIG. 5, for example, for the same voltage or the same current and thus the same magnetic field strength. The actuation element 6 in the embodiments shown in FIGS. 5 and 6 also preferably has a securing section 65.
LIST OF REFERENCE SIGNS
[0033] 2—stator [0034] 4—rotor [0035] 5—main body [0036] 6—actuation element [0037] 6—coil arrangement [0038] 8—shoe element [0039] 9—first transmission section [0040] 10—second transmission section [0041] 12—actuating unit [0042] 25—stator anti-rotation safeguard [0043] 42—rotor bolt [0044] 43—rotor recess [0045] 51—opening [0046] 55—main-body anti-rotation safeguard [0047] 62—actuation bolt [0048] 63—actuation recess [0049] 65—securing section [0050] 71—permanent magnet [0051] 72—windings [0052] 74—terminal [0053] 85—shoe anti-rotation safeguard [0054] B—actuation axis [0055] D.sub.4 —mean engagement diameter [0056] D.sub.7 —mean coil diameter
