Multi-disc brake, especially dual disc brake, with inclined ball track

WO2026093198A3PCT designated stage Publication Date: 2026-06-25RENK AG

Patent Information

Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
RENK AG
Filing Date
2025-10-27
Publication Date
2026-06-25

AI Technical Summary

Technical Problem

Multi-disc brakes, particularly double-disc brakes, experience significant wear and require frequent maintenance due to uneven distribution of braking force and inadequate cooling, leading to overheating and contamination.

Method used

A multi-disc brake design featuring an inclined ball track with split actuation, direct liquid cooling, and encapsulated coolant supply, ensuring even wear distribution and efficient cooling through independent actuation and symmetrical clamping mechanisms.

Benefits of technology

The design achieves more uniform wear, reduced maintenance intervals, and improved braking performance by evenly distributing braking force and maintaining optimal operating temperatures, preventing overheating and contamination.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention relates to a multi-disc brake, in particular a dual disc brake, (1) for a closed and / or dry-running brake system of a superimposed steering gear, having a clamping mechanism (2), wherein the clamping mechanism (2) has a clamping element of a rotor (11, 12) and a clamping element of a stator (21, 22); an inclined ball track (3, 3a, 3b), which is designed to actuate the clamping mechanism (2) axially with respect to a rotation of the rotor; and a liquid cooling system for the clamping element of the stator (21, 22).
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Description

[0001] 119472P504PC 1 / 19 RENK GmbH

[0002] Description

[0003] Multi-disc brake, especially double-disc brake, with inclined ball track

[0004] The present invention relates to a multi-disc brake, in particular a double-disc brake, with an inclined ball track, in particular a vehicle, further in particular with a superimposed transmission, which has such a multi-disc brake, in particular a double-disc brake.

[0005] Multi-disc brakes typically wear out.

[0006] The object of the present invention is, in particular, to improve a multi-disc brake, in particular a double-disc brake, in particular a superimposed steering gear, further in particular a multi-disc brake, in particular a double-disc brake, for a vehicle, further in particular for a superimposed (steering) gear for a vehicle, in particular to improve or minimize wear of the multi-disc brake, in particular double-disc brake and / or to increase a maintenance interval, in particular with regard to the prior art.

[0007] This problem is solved by a multi-disc brake, in particular a dual brake, with the features of claim 1. Claims 19, 21 and 23 protect a braking system or a superimposed steering gear with a multi-disc brake, in particular a dual disc brake, or a braking system; in particular a vehicle with a corresponding multi-disc brake, in particular a dual disc brake. The dependent claims relate to advantageous embodiments.

[0008] According to one embodiment of the present invention, a multi-disc brake, particularly for a superimposed steering gear, is provided. In one embodiment, the multi-disc brake has a clamping mechanism, wherein the clamping mechanism comprises a clamping element of a rotor, which can in particular (also) be referred to as a rotor clamping element or is a rotor clamping element, and a clamping element of a stator, which can in particular (also) be referred to as a stator clamping element 119472P504PC 2 / 19 RENK GmbH or is a stator clamping element. In one embodiment, the multi-disc brake has an angular contact ball track configured to actuate the clamping mechanism, in particular axially with respect to a rotation of the rotor. In one embodiment, the multi-disc brake has, in particular, direct, liquid cooling of the clamping element of the stator or of the stator clamping element.In one embodiment, the multi-disc brake has a cooling system for the rotor, in particular indirect cooling, especially liquid cooling and / or air cooling. In another embodiment, the multi-disc brake is a double-disc brake or is designed as a double-disc brake. In another embodiment, the multi-disc brake, in particular the skewed ball track, and further in particular the (respective) ball track(s), of the skewed ball track mechanism has a split actuation and / or, in particular the multi-disc brake, and further in particular the clamping elements, has (each) a separately actuated actuation.

[0009] Advantageously, this allows for a more compact design in one version. In another version, this also advantageously enables more uniform wear and / or a more uniform distribution of braking force, and in particular, makes cooling easier to implement.

[0010] The term "direct liquid cooling," as used herein, preferably means that the liquid cooling acts directly on the stator clamping element and, in particular, does not cool via an intermediate heat transfer element or an intermediate volume. In one embodiment, the cooling system comprises a coolant, such as, in particular, a liquid or a liquid mixture, water, or a special refrigerant, which comes into contact, in particular directly, with the object or element to be cooled, especially the stator clamping element, and furthermore, in particular, without the need for an additional heat exchanger. In another embodiment, "direct cooling" means that the coolant does not flow around the brake, but rather allows it to run dry, furthermore, in particular, through the closed design of the direct cooling system (of the stator).

[0011] In one embodiment, the cooling system of the multi-disc brake is encapsulated, in particular such that a coolant is used, at least essentially, only for the direct cooling of the stator(s) of the multi-disc brake. In another embodiment, the stator clamping element has at least one cooling channel.In one embodiment, the multi-disc brake has a coolant supply, in particular a plug-in tube, or in particular a flexible element for coolant supply, further in particular a hose-like element or a bellows supply, which is arranged on the clamping mechanism, wherein the coolant supply, in particular the plug-in tube, or in particular the flexible element for coolant supply, further in particular the hose-like element or the bellows supply, is configured to provide a fluid connection to the at least one cooling channel of the clamping element of the stator. In one embodiment, the cooling channel has, in particular at least, a cooling fin and / or, in particular at least, a cooling rib.

[0012] The term "encapsulated," as used herein, is preferably to be understood as a (cooling) system, particularly a closed one, that protects or prevents a coolant within the system from contamination. In particular, "encapsulated" in one embodiment refers to the prevention of contamination, specifically that the encapsulated cooling system is designed to prevent the ingress of dirt and / or contaminants into the cooling system. In one embodiment, the encapsulated cooling system is not connected to a brake actuation, particularly a brake hydraulic system, and is furthermore, in particular, hydraulically separated from an actuation or actuation circuit of the multi-disc brake, particularly a dual-disc brake, and furthermore, in particular, independent or separate. The use of the term "dual-disc brake" herein is to be understood, in particular, without limitation of generality.

[0013] The term "coolant supply," as used herein, is preferably to be understood as an element designed to establish a fluid connection, in particular a liquid-tight connection, especially between a liquid cooling system and an arrangement / device designed or configured to supply coolant to the multi-disc brake, in particular a dual-disc brake, and furthermore, is used specifically for this purpose. In one embodiment, the coolant supply has a seal 119472P504PC 4 / 19 RENK GmbH for this purpose. In another embodiment, the coolant supply is designed to compensate for a clamping movement of the clamping element, in particular such that the fluid connection provided, in particular by the coolant supply, can be maintained. In another embodiment, the coolant supply is used to maintain the fluid connection.In one embodiment, the coolant supply, particularly with its axis, is arranged in the axial direction (particularly with respect to the multi-disc brake, especially a double-disc brake). In another embodiment, each clamping element of the stator or each stator clamping element of the multi-disc brake, especially a double-disc brake, has a coolant supply, in particular a plurality of coolant supplies, which are arranged (in particular) circumferentially, and in particular uniformly, distributed on the stator clamping element.

[0014] The term "plug-in tube," as used herein, is preferably to be understood as a tube-like element designed to establish a fluid connection, in particular a fluid-tight connection. In one embodiment, the plug-in tube has a seal for this purpose. In another embodiment, the plug-in tube is designed to compensate for a clamping movement of the clamping element, in particular such that the fluid connection provided, in particular by the plug-in tube, can be maintained or is maintained. In one embodiment, the plug-in tube is arranged, in particular with its axis, in the axial direction. In one embodiment, each clamping element of the stator or each stator clamping element of the multi-disc brake, in particular a double-disc brake, has a plug-in tube, in particular a plurality of plug-in tubes, which are arranged circumferentially, in particular uniformly, distributed on the stator clamping element.

[0015] Advantageously, this allows the multi-disc brake, especially the double-disc brake, to be cooled more easily in one design, and in particular makes it more efficient compared to a wet-running brake.

[0016] In one embodiment, the split or separately actuated actuation has a coupling element that realizes, or is configured for, a particularly independent return of the (respective) actuation and acts, or can act, particularly in the axial direction of the multi-disc brake and / or in the circumferential direction, particularly in and / or against the direction of rotation of the multi-disc brake (119472P504PC 5 / 19 RENK GmbH). In another embodiment, the actuation has a coupling element, in particular a beam-like (coupling) element, that connects the at least two parts of the split actuation, which are particularly configured, in particular each, to actuate one of the skewed ball tracks of the

[0017] To realize an inclined ball track mechanism, at least in its essentials, coupled (to each other), in embodiments, by means of a restoring element which in particular has a spring element, further in particular at least one spring, or the like.

[0018] In one embodiment, this advantageously allows for the implementation of an actuation mechanism that is particularly adapted to the operation, especially such that wear of the clamping mechanism can be adjusted using the split actuation or that the actuation can be used for this purpose. Advantageously, in one embodiment, the multi-disc brake can be reset, particularly after actuation, especially braking, using the coupling element.

[0019] In one embodiment, the skewed ball track is arranged centrally, particularly with respect to two stator clamping elements and two rotor clamping elements of the multi-disc brake, in particular a double-disc brake; in one embodiment, the skewed ball track is arranged in axial sequence between a first rotor clamping element and a first stator clamping element and a second stator clamping element and a second rotor clamping element, wherein the stator clamping elements each enclose the rotor clamping element, in particular with their, furthermore, directly, cooled working elements or adjustments.In one embodiment, the skewed ball track is centrally arranged, particularly with respect to two stator clamping elements and two rotor clamping elements of the multi-disc brake, particularly a double-disc brake. In one embodiment, the skewed ball track is arranged axially between a first rotor clamping element and a first stator clamping element, wherein the first stator clamping element, in particular, surrounds the first rotor clamping element, at least substantially, and a second stator clamping element and a second rotor clamping element, wherein the second stator clamping element, in particular, surrounds the second rotor clamping element, at least substantially. In one embodiment, the rotor clamping elements and the stator clamping elements are, at least substantially, symmetrical about 119472P504PC 6 / 19 RENK GmbH.

[0020] A clamping mechanism is arranged, in particular the skewed ball track is arranged centrally between the clamping elements, wherein in one embodiment a clamping mechanism is arranged on each side of the skewed ball track. In one embodiment, each coolant supply has its own, in particular its own, coolant supply. In one embodiment, a first coolant supply on a first axial side (with respect to a centrally arranged skewed ball track) has a first coolant supply, and a second coolant supply on a second axial side, which differs from the first axial side, has a second coolant supply. In one embodiment, the first coolant supply and the second coolant supply have a common, in particular, coolant supply. In one embodiment, several coolant supplies are arranged, in particular evenly distributed around the circumference.In one embodiment, the multi-disc brake, particularly a double-disc brake, has one or more channels for supplying (fluid) coolant to one or more coolant inlets. In one embodiment, each connecting tube has its own coolant supply. In one embodiment, a first connecting tube has a first coolant supply on a first axial side (with respect to a centrally arranged spherical track), and a second connecting tube has a second coolant supply on a second axial side that differs from the first axial side. In one embodiment, the first connecting tube and the second connecting tube have a common coolant supply. In one embodiment, several connecting tubes are arranged, particularly evenly distributed around the circumference.In one embodiment, the multi-disc brake, in particular the double-disc brake, has one or more channels for the (fluid) supply of one or more connecting tubes.

[0021] Advantageously, this design allows for a more even distribution of braking force across the clamping mechanisms, resulting in less wear and / or less maintenance, and enabling the transmission of a high or higher braking force, particularly for a longer period of time.

[0022] In one version, the multi-disc brake, in particular

[0023] Dual disc brake, designed as a parking and / or service brake. 119472P504PC 7 / 19 RENK GmbH

[0024] This allows, in one embodiment, a more efficient parking brake function to be provided, particularly for heavy commercial vehicles that are stationary, or must remain stationary, for extended periods. Furthermore, in one embodiment, this enables more efficient and / or effective braking performance, especially at high speeds, without the multi-disc brake, particularly a dual-disc brake, overheating and / or becoming contaminated, particularly by contamination of the cooling system.

[0025] In one embodiment, at least one of the clamping elements has a brake lining, in particular the clamping element of the rotor. In another embodiment, the clamping element of the rotor has (at least) a brake lining on each of the axial sides of the clamping element.

[0026] This advantageously allows for simpler maintenance, particularly of the brake pads, especially maintenance of multi-disc brakes, particularly dual-disc brakes, which require little or no interaction with the cooling system. Advantageously, the multi-disc brake described herein, particularly the dual-disc brake, enables longer maintenance intervals, especially due to a more even load distribution on the brake pads, and in particular, more even wear of the brake pads.

[0027] In one embodiment, the inclined ball track is designed to be centrally controlled, in particular in such a way that the control of the inclined ball track acts, or can act, at least substantially, centrally between the stator clamping elements and the rotor clamping elements.

[0028] Advantageously, this design allows for simpler actuation of the control mechanism, and in particular, ensures that the effect of the actuation is distributed, especially evenly, across the rotor clamping elements. 119472P504PC 8 / 19 RENK GmbH

[0029] In one embodiment, the inclined ball track has a split actuation mechanism that can actuate at least one ball track independently of another ball track of the inclined ball track or the inclined ball track mechanism, and is specifically designed or used for this purpose. In another embodiment, the inclined ball track has two or more tracks for balls, wherein the tracks can be actuated independently of, and in particular at least, one of the other tracks, or are specifically designed for this purpose. In another embodiment, the multi-disc brake can have two tracks of the inclined ball track that can be actuated at least substantially independently of each other. In another embodiment, the multi-disc brake can have three or more tracks of the inclined ball track that can be actuated at least substantially independently of each other.In one embodiment, one or more rotors can be arranged axially along the (respective) track, particularly on an axial side of the ball track, which can be braked, in particular by means of a (braking) actuation of the (respective) track. In another embodiment, two or more tracks (of an inclined ball track or an inclined ball track mechanism) can enclose one or more rotors, in particular such that the rotors, in particular the clamping elements, are arranged between the two or more tracks. In another embodiment, one or more tracks (of the inclined ball track or the inclined ball track mechanism) can be arranged between the rotors, in particular the clamping elements, in particular such that the track and / or tracks are surrounded symmetrically or asymmetrically (in the axial direction) by the rotors, in particular the clamping elements, and / or are arranged symmetrically or asymmetrically between the rotors, in particular the clamping elements.

[0030] Advantageously, this allows a braking force to be provided more easily in one embodiment, and in particular, braking can be more precise. Furthermore, it prevents, at least substantially, uneven wear of the brake, and in particular, brake wear can be made more uniform. In one embodiment, this advantageously allows braking to be applied more as needed.

[0031] In one version, the multi-disc brake features, in particular

[0032] Double disc brake, a coupling element, in particular a spring package, which is designed in particular for resetting the multi-disc brake, in particular double disc brake, in particular for resetting the clamping mechanism.

[0033] Advantageously, this allows, in one design, the multi-disc brake, especially the double-disc brake, to be operated more reliably.

[0034] In one embodiment, the clamping element, in particular the respective one, is formed, at least essentially, around the perimeter.

[0035] In one embodiment, the clamping mechanism is arranged between the rotors and / or the multi-disc brake, in particular double-disc brake, is at least essentially symmetrical.

[0036] In one embodiment, the symmetrical design of the multi-disc brake, particularly a dual-disc brake, advantageously allows for a balanced distribution of braking force between the two discs, leading to improved braking performance and / or reduced wear. Furthermore, in another embodiment, the symmetry of the braking mechanism advantageously results in more consistent and / or predictable behavior, reducing the risk of unforeseen malfunctions, failures, or other disruptions, and improving the overall reliability of the multi-disc brake, particularly a dual-disc brake.

[0037] In one embodiment, the multi-disc brake, in particular a double-disc brake, comprises at least substantially a light metal; in particular, the multi-disc brake, in particular a double-disc brake, and / or a housing of the multi-disc brake, in particular a double-disc brake, is in one embodiment, at least substantially, made of, in particular at least, a light metal and / or can be manufactured from. In one embodiment, the housing has a passage, in particular a single- or multi-channel arrangement, which is configured to provide liquid cooling 119472P504PC 10 / 19 RENK GmbH, in particular to provide liquid for cooling the stator clamping element or the clamping element of the stator. In one embodiment, the multi-disc brake, in particular a double-disc brake, in particular the liquid cooling, is configured to be supplied with coolant from a gearbox.

[0038] In one embodiment, this can advantageously be achieved through the higher efficiency of the multi-disc brake, in particular the double-disc brake, described herein, particularly by enabling the temperature to be kept, at least substantially, below 600°C or below 500°C using the multi-disc brake, in particular the double-disc brake, described herein. This, in one embodiment, allows the multi-disc brake, in particular the double-disc brake, to be manufactured with reduced weight, in particular with a lower weight.

[0039] According to one embodiment of the present invention, a braking system for a superimposed transmission is provided. In one embodiment, the braking system comprises a multi-disc brake, in particular a double-disc brake, or, more specifically, two multi-disc brakes, in particular double-disc brakes.

[0040] In one embodiment, the braking system has a spring accumulator; in particular, the braking system is designed as a spring accumulator braking system.

[0041] According to one embodiment of the present invention, a superimposed steering gear, particularly for a vehicle, is provided. In one embodiment, the superimposed steering gear includes a braking system as described herein. In another embodiment, the superimposed steering gear is configured to provide liquid cooling, particularly for cooling the braking system, and further, in particular, for cooling the stator of the multi-disc brake, especially a dual-disc brake, of the braking system.

[0042] In one version, the multi-disc brake, in particular

[0043] Dual disc brake integrated into the housing of the superimposed steering gear, in particular 119472P504PC 11 / 19 RENK GmbH in the gearbox housing. In one embodiment, the multi-disc brake, in particular the dual disc brake, is arranged on the housing of the superimposed steering gear, in particular on the gearbox housing. In one embodiment, in particular only, a part of the multi-disc brake, in particular the dual disc brake, is integrated into and / or arranged on the housing of the superimposed steering gear, in particular in the gearbox housing.

[0044] Advantageously, this allows a more compact superimposed steering gear with a multi-disc brake, in particular a double-disc brake, to be realized in one embodiment, in particular a multi-disc brake, in particular a double-disc brake, to be designed or be more compact.

[0045] According to one embodiment of the present invention, a vehicle is provided, in particular a vehicle with a superimposed steering gear (as described herein). In one embodiment, the superimposed steering gear has a braking system or a multi-disc brake, in particular a dual-disc brake, as described herein.

[0046] Advantageously, this allows the vehicle to have, in particular, improved braking behavior, and in particular to be able to brake more easily.

[0047] Further advantages and features will become apparent from the dependent claims and the exemplary embodiments. These are shown, in part schematically:

[0048] Fig. 1: a multi-disc brake, in particular a double-disc brake, according to an embodiment of the present invention in an open position; and

[0049] Fig. 2: a multi-disc brake, in particular a double-disc brake, according to an embodiment of the present invention in a closed or brake-actuated position; and

[0050] Fig. 3: A detailed view of an inclined ball track according to an embodiment of the present invention. 119472P504PC 12 / 19 RENK GmbH

[0051] Fig. 1 shows a multi-disc brake, in particular a double-disc brake, 1 with a clamping mechanism 2, wherein the clamping mechanism 2 comprises a first rotor clamping element 11 and a second rotor clamping element 12. Furthermore, the clamping mechanism 2 comprises a first stator clamping element 21 and a second stator clamping element 22. A housing 30 is also shown, which, in one embodiment, encloses or surrounds the multi-disc brake, in particular a double-disc brake, 1. The housing 30 has a passage 31, in particular single- or multi-channel, especially with a plurality of channels, which is configured to supply coolant to the stator clamping elements 21, 22, in particular to provide a fluid connection. For particularly effective liquid cooling, the stator clamping elements 21, 22 each have a cooling channel, which is further configured, in particular, to be in fluid connection with the channel of the housing 30.Furthermore, a connecting tube 40 is shown on each side, which enables a fluid connection between the (shown) passage 31 (see arrow) of the housing 30, which can be extended, particularly when the brake is applied. In the open position, as shown in Fig. 1, the rotor clamping elements, which are shown with brake linings, can rotate. If the slant ball track 3, which in one embodiment is particularly centrally actuated, is activated, this actuates the clamping mechanism 2. Furthermore, an arrangement of a gearbox or an arrangement on a gearbox housing 32, in particular a superimposed steering gear, is indicated in Fig. 1 on the left side of the blade. Even though the figures refer to embodiments with double disc (brakes), this applies without limitation of generality. In embodiments, the multi-disc brakes can have an even or odd number of brake discs, which can be, or are, arranged symmetrically or asymmetrically.

[0052] Fig. 2 shows the multi-disc brake, in particular the double-disc brake, 1 of Fig. 1 in a closed, actuated, or braking state. It can be seen that the connecting tubes 40 compensate for the movement of the actuation of the clamping mechanism, so that, in particular, the fluid connection between passage 31 and the cooling channel of the stator clamping elements 21, 22 is maintained. Specifically, in the case of an axial movement of the clamping mechanism, especially of the stator clamping elements, this axial movement is compensated for by means of the connecting tube(s) 40. For this purpose, the connecting tube 40, in one embodiment, has a seal, which is particularly suitable. 119472P504PC 13 / 19 RENK GmbH

[0053] Fig. 3 shows a detailed view of an inclined ball track, wherein the actuation or actuation mechanism of the inclined ball track is independently operable for the tracks, in particular each of the tracks, and is specifically designed or used for this purpose. For this purpose, actuation elements 3d and 3e are shown in Fig. 3, in particular, by means of which the (respective) inclined ball track can be actuated or which are designed for this purpose. In one embodiment, an actuation, in particular an independent actuation, has a compensating bearing 3c, which is specifically designed to compensate for the actuation of the inclined ball track, at least substantially, and in particular to ensure actuation, in particular only, of one side of an inclined ball track. Furthermore, a coupling element 3f, which can be or is specifically designed as a (tension) spring, is shown in Fig. 3.The coupling element 3f is, in one version, specifically designed or used for resetting the inclined ball track.

[0054] In the present disclosure, "has an X" does not generally imply an exhaustive list, but is a shorthand for "has at least one X" and also includes "has two or more X" as well as "has Y in addition to X". Although exemplary implementations were explained in the preceding description, it should be noted that a multitude of variations are possible. Furthermore, it should be noted that the exemplary implementations are merely examples and are not intended to limit the scope of protection, applications, or structure in any way.Rather, the preceding description provides the skilled person with a guideline for implementing at least one exemplary embodiment, whereby various modifications, particularly with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as defined by the claims and these equivalent combinations of features. 119472P504PC 14 / 19 RENK GmbH.

[0055] List of reference signs

[0056] 1 Multi-disc brake

[0057] 2 Clamping mechanism 3, 3a, 3b Inclined ball track

[0058] 3c Compensating bearing

[0059] 3D, 3D actuating element

[0060] 3f coupling element

[0061] 11 first rotor clamping element 12 second rotor clamping element

[0062] 21 first stator terminal element

[0063] 22 second stator terminal element

[0064] 30 cases

[0065] 31 Passage / Coolant supply 32 Gearbox housing

[0066] 40 plug-in pipe

Claims

119472P504PC 15 / 19 RENK GmbH Patent claims 1. Multi-disc brake (1) for a closed and / or dry-running brake system of a superimposed steering gear, comprising: - a clamping mechanism (2) wherein the clamping mechanism (2) comprises a clamping element of a rotor (11 , 12) and a clamping element of a stator (21 , 22); - an inclined ball track (3, 3a, 3b) configured to actuate the clamping mechanism (2) axially with respect to a rotation of the rotor; and - a liquid cooling of the clamping element of the stator (21 , 22) and / or wherein the slant ball track (3, 3a, 3b) has a split actuation.

2. Multi-disc brake (1) according to the preceding claim, characterized in that if the slant ball track (3, 3a, 3b) has a split actuation, the actuation has a coupling element in the axial direction and / or in the circumferential direction.

3. Multi-disc brake (1) according to the preceding claim, characterized in that the actuation has a coupling element in each case.

4. Multi-disc brake (1) according to the preceding claims 2 or 3, characterized in that the coupling element has or is a return mechanism.

5. Multi-disc brake (1) according to one of the preceding claims, characterized in that the liquid cooling is encapsulated and / or that the clamping element of the stator (21, 22) has at least one cooling channel, and / or wherein the multi-disc brake (1) has a coolant supply arranged on the clamping mechanism (2), wherein the coolant supply is configured to provide a fluid connection to the at least one cooling channel of the clamping element (21, 22). 119472P504PC 16 / 19 RENK GmbH 6. Multi-disc brake (1) according to the preceding claim, characterized in that the coolant supply comprises a plug-in tube (40), a flexible element, a hose-like element or a bellows supply.

7. Multi-disc brake (1) according to one of the preceding claims, characterized in that the inclined ball track (3, 3a, 3b) is arranged centrally.

8. Multi-disc brake (1) according to the preceding claim, characterized in that the inclined ball track (3, 3a, 3b) is arranged to be centrally controlled and / or that the clamping mechanism (2) is arranged between the rotors.

9. Multi-disc brake (1) according to the preceding claim, characterized in that the multi-disc brake (1) is symmetrically constructed.

10. Multi-disc brake (1) according to one of the preceding claims, characterized in that the multi-disc brake (1) has a housing (30) and that the housing (30) has a passage (31), in particular single-channel or multi-channel, which is in fluid communication with the liquid cooling, and / or wherein the housing is made of a light metal, in particular aluminium.

11. Multi-disc brake (1) according to one of the preceding claims, characterized in that the multi-disc brake (1) has a coupling element which is designed to reset the multi-disc brake (1).

12. Multi-disc brake (1) according to the preceding claim, characterized in that the coupling element is designed to reset the clamping mechanism (2).

13. Multi-disc brake (1) according to the preceding claims 11 or 12, characterized in that the coupling element is a spring assembly. 119472P504PC 17 / 19 RENK GmbH 14. Multi-disc brake (1) according to one of the preceding claims, characterized in that the at least one clamping element of the stator (21 , 22) is designed circumferentially.

15. Multi-disc brake (1) according to one of the preceding claims, characterized in that the multi-disc brake (1) is designed as a parking and / or service brake.

16. Multi-disc brake (1) according to one of the preceding claims, characterized in that at least one of the clamping elements (11 , 12, 21 , 22) has a brake lining.

17. Multi-disc brake (1) according to the preceding claim, characterized in that the clamping element of the rotor (11 , 12) has a brake lining.

18. Multi-disc brake according to one of the preceding claims, wherein the multi-disc brake is a double-disc brake.

19. Braking system for a superimposed steering gear, comprising at least one multi-disc brake (1) or at least two multi-disc brakes according to one of the preceding claims.

20. Braking system according to the preceding claim, wherein the braking system comprises a spring accumulator.

21. Superimposed steering gear for a vehicle, comprising at least one braking system according to one of the preceding claims 19 or 20.

22. Superimposed steering gear according to the preceding claim, wherein the superimposed steering gear is configured to provide liquid cooling and / or wherein part of the multi-disc brake (1) is integrated in and / or on a housing of the superimposed steering gear. 119472P504PC 18 / 19 RENK GmbH 23. Vehicle comprising a superimposed steering gear according to the preceding claim.