Radial piston machine with multi-disc brake

Abstract

The invention relates to a radial piston machine (10) having a multi-disc brake (57), the brake disc assembly (50) of which interacts with a first ring section (35) on a drive shaft (30) and with a second ring section (25) on a housing (20). According to the invention, the brake disc assembly (50) is arranged inside the brake chamber (58), the first and second ring sections (35; 25) each delimit a brake chamber (58) in sections, the disc section (34), the spring (53), the brake piston (54) and the brake disc assembly (50) being arranged next to one another in a specified sequence along the axis of rotation (13) such that a force of the spring (53) can be transmitted to the brake disc assembly (50).

Description

Technical Field

[0001] The invention relates to a radial piston machine according to the preamble of claim 1 . Background Art

[0002] A radial piston machine with a multi-disc brake is known from EP 2 841 763 B1. The corresponding construction of the radial piston machine is characterized in that it requires a particularly small installation space in the direction of the axis of rotation. This is primarily achieved in that the brake disc assembly of the multi-disc brake is arranged around at least one rotary bearing of the drive shaft. The drive shaft comprises a first ring section for this purpose, which is integrally connected to the shaft section via a disc section. One half of the brake disc is connected to the first ring section in a rotationally fixed manner, and the other half of the brake disc is connected to the second ring section in a rotationally fixed manner, the second ring section being a component of the housing of the radial piston machine. The multi-disc brake is preloaded into a closed state using a butterfly spring. The multi-disc brake can be switched to an open state by applying pressure to the brake chamber delimited by the annular brake piston. Summary of the invention

[0003] One advantage of the invention is that the radial piston machine requires less installation space in the direction of the axis of rotation. In addition, its cost-effectiveness is greatly increased, since it comprises fewer components, in particular very expensive components can be omitted. In this context, the expensive sliding ring seal (double cone seal) from EP 2841763 B1 should be mentioned in particular, with which the gap between the first ring section and the housing is sealed. In addition, a separate oil reservoir for lubricating the brake disc can be omitted.

[0004] According to claim 1, the brake disc assembly is arranged inside the brake chamber, wherein the first and second ring segments respectively limit the brake chamber in sections, wherein the disc segments, the spring, the brake piston and the brake disc assembly are arranged side by side in a specified order along the rotation axis so that the force of the spring can be transmitted to the brake disc assembly.

[0005] The radial piston machine is preferably operated with a pressurized fluid, which is most preferably a liquid and in particular a hydraulic oil. The radial piston machine is preferably operated as a motor, which can also be operated as a pump, wherein hybrid forms are also conceivable.

[0006] It is conceivable that the radial piston machine includes a valve device, by means of which a plurality of effective displacements can be switched between, in that a single or all working chambers are temporarily closed. It is conceivable that an idling operation is realized, in which case all working chambers are temporarily closed, so that the rotor can idling without a fluid flow between the first and second working interfaces. In all other positions of the valve device, the rotation of the rotor is preferably accompanied by a fluid flow between the first and second working interfaces. The spring is preferably designed as a butterfly spring. The shaft section, the disk section and the first ring section of the drive shaft are preferably connected to each other in one piece.

[0007] The brake piston is preferably movable relative to the drive shaft in the direction of the rotation axis. The corresponding movement path is preferably designed to be so large that the multi-disk brake can be switched between a closed state and an open state. The fluid distributor and the at least one rotary bearing are preferably arranged on opposite sides of the rotor in the direction of the rotation axis.

[0008] Preferably, at least one rotary bearing is arranged radially between the shaft section and the second ring section with respect to the rotation axis. Most preferably, first and second rotary bearings are provided which are arranged radially between the shaft section and the second ring section with respect to the rotation axis.

[0009] Advantageous developments and improvements of the invention are stated in the dependent claims.

[0010] It can be provided that the brake piston bears sealingly with its radial outer circumferential surface against the first ring section and that the brake piston bears sealingly with its radial inner circumferential surface against the shaft section, so that the drive shaft and the brake piston bound a spring chamber in which the spring is arranged. As a result, there is no relative rotation between the brake piston and the drive shaft, so that the brake piston can be sealed without problems, in particular the sealing concept of the brake piston known from EP 2841763 B1 can be used.

[0011] A first fluid channel can be provided which extends from the spring chamber to the housing interior completely within the drive shaft. Without the first fluid channel leading from the spring chamber to the housing interior, the spring chamber would be closed almost tightly. Unavoidable leakage into the spring chamber could result in an obstruction of the intended movement of the brake piston. This is reliably prevented by the first fluid channel. The housing preferably has a leakage connection which opens into the interior, wherein a substantially pressureless tank can be connected to the leakage connection, so that the interior is also substantially pressureless and leakage occurring in the interior can flow out into the tank.

[0012] A separate closing ring can be provided, which is arranged radially between the first and second ring sections with respect to the axis of rotation, wherein the closing ring delimits the brake chamber in sections, wherein the brake disc assembly is arranged in the direction of the axis of rotation between the brake piston and the closing ring so that the force of the spring can be supported on the closing ring, wherein the closing ring is supported in the direction of the axis of rotation on the first ring section. If a drive shaft, which is preferably integral, is used, the closing ring facilitates the installation of the brake disc assembly, the brake piston and the spring in the drive shaft. In principle, the assembly comprising the drive shaft and the closing ring can also be divided in other ways. However, the proposed division results in the best rigidity and strength of the radial piston machine.

[0013] It can be provided that the closing ring is supported on the first ring section in the direction of the rotation axis by means of a separate securing ring, wherein the corresponding connection is designed so that the closing ring is also connected to the first ring section in a rotationally fixed manner with respect to the rotation axis. The securing ring requires very little installation space, but it can still reliably transmit the forces occurring during operation. The rotationally fixed connection preferably occurs by means of a friction lock. It goes without saying that the rotationally fixedly transmittable torque is limited upwards. During operation, preferably only the friction torque of the different sealing rings acts on the closing ring, so that the transmittable torque is not exceeded.

[0014] It can be provided that the closing ring is connected to the first ring section on the radial outside in a rotationally fixed manner and that at least one dynamic sealing ring is arranged on the radial inside of the closing ring between the closing ring and the second ring section. A dynamic sealing ring is to be understood as a sealing ring in which relative movements occurring in the sealing contact only cause slight wear, which has a negligible effect on the required sealing effect over a long period of time. Within the scope of the invention, the first dynamic sealing ring and the fourth sealing ring are in any case exposed to the high pressure of the brake chamber, which also additionally increases the above-mentioned wear. EP 2841763 B1 avoids precisely this unfavorable combination.

[0015] It can be provided that at least one dynamic sealing ring comprises a first and a second sealing ring, which are arranged side by side in the direction of the axis of rotation, so that a leakage chamber is obtained between the first and the second sealing rings, wherein the first sealing ring directly seals the brake chamber, wherein the first sealing ring is configured so that a leakage flow can be obtained at the sealing joint when the brake chamber is under pressure, wherein the second sealing ring is configured to be fluid-tight, wherein the leakage chamber is connected to the inner chamber of the housing via a second fluid channel. The second sealing ring is preferably configured as a radial shaft sealing ring. It is therefore not particularly pressure-resistant, but it is still permanently sealed despite the rotational movement between the housing and the drive shaft. The first sealing ring is preferably configured as a compression sealing ring, whose sealing effect is activated by the pressure difference between the pressure chamber and the leakage chamber. The corresponding first sealing ring is known from the technical bulletin "TurconBuffer Ring" of Trelleborg (version number: EPH035_08; August 2021). The leakage flow causes only a small amount of wear on the first sealing ring despite the high pressure. However, due to the presence of the second fluid channel, no pressure is formed in the leakage chamber, so that the second sealing ring does not need to be subjected to any compressive stress. The second fluid channel preferably extends completely within the second ring section. It preferably opens into the inner chamber between the first and second rotary bearings. It goes without saying that the value of the leakage flow depends on the pressure in the brake chamber. The first sealing ring is preferably designed so that there is a leakage flow at the usual brake pressure.

[0016] It can be provided that a third sealing ring is arranged between the closing ring and the housing in the direction of the axis of rotation. The third sealing ring preferably comprises an annular rubber sealing lip which is protected by a sheet metal ring (blechring) against particles penetrating from the outside of the radial piston machine. The third sealing ring serves primarily to protect the second sealing ring against particles penetrating from the outside, so that the second sealing ring has the longest possible service life. With the preferred design of the third sealing ring, it can be arranged as proposed on the one hand, and its function is permanent on the other hand.

[0017] It can be provided that a fourth sealing ring is arranged between the shaft section and the second ring section, which seals the brake chamber in a fluid-tight manner, so that a leakage flow is obtained at the sealing joint when the brake chamber is under pressure. The fourth sealing ring preferably uses the same sealing principle as the first sealing ring, wherein the fourth sealing ring is preferably designed as a compression sealing ring, in particular a "buffer ring". Since the fourth sealing ring directly adjoins the housing interior, no further measures for conducting away the leakage flow are required. The pressure in the brake chamber preferably acts directly on the fourth sealing ring.

[0018] It can be provided that the end face of the first ring section facing away from the disk section cooperates with the housing in the form of a labyrinth seal. With the labyrinth sealing ring, it should be achieved that as few particles as possible can reach the third sealing ring from the outside, so that the second sealing ring is protected as much as possible.

[0019] It can be provided that a first fastening flange is arranged on the outside of the housing, by means of which the radial piston machine can be fastened to a superordinate component, wherein a brake interface is arranged on the first fastening flange, wherein the brake interface is fluidically connected to the brake chamber. The superordinate component is, for example, a frame of a hydraulically driven vehicle, wherein the radial piston machine is operated as a radial piston motor, which directly drives an associated wheel or an associated traction chain of the vehicle. The first ring section of the drive shaft can be provided with a second fastening flange, on which, for example, the wheels are fastened. The brake interface is preferably arranged on the outer circumferential surface of the first fastening flange. The brake interface is preferably permanently fluidically connected to the brake chamber, most preferably via a third fluid channel, which extends only in the housing, in particular in the third housing part.

[0020] It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively stated combination but also in other combinations or alone without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be explained in more detail below with reference to the accompanying drawings, wherein:

[0022] Figure 1 shows a perspective view of a radial piston machine according to the invention;

[0023] Figure 2 Shown in accordance with Figure 1 A longitudinal section of a radial piston machine; and

[0024] Figure 3 In the area of ​​the multi-disk brake, the Figure 2 Enlarged truncation. DETAILED DESCRIPTION

[0025] Figure 1 1 shows a perspective view of a radial piston machine 10 according to the invention. The radial piston machine 10 comprises a housing 20 which in this context consists of a first, a second and a third housing part 21; 22; 23 which are arranged side by side along the axis of rotation 13 and are fixedly connected to one another. The first and second working interfaces 11; 12 are arranged outside the first housing part 21, and a fluid distributor ( Figure 1 The inner circumferential surface of the second shell part 21 forms a control surface ( Figure 2 26), which makes the piston ( Figure 2 The third housing part is fastened with two rotating bearings ( Figure 231; 32), the drive shaft 30 is rotatably supported about the rotation axis 13 by means of these two rotary bearings. A first fastening flange 15 is arranged on the housing 20, in particular on the third housing part 23, by means of which the radial piston machine 10 can be fastened to an upper component, such as a frame of a hydraulically driven vehicle. A second fastening flange 16 is arranged on the drive shaft 30, by means of which the radial piston machine 10 can be fastened to a lower component, such as a wheel of the vehicle.

[0026] It has proven to be advantageous within the scope of the invention if the brake interface 17 , by means of which the multi-disk brake in this case is hydraulically released, is arranged on the first fastening flange 15 , in particular on its outer circumferential surface.

[0027] Figure 2 Shown in accordance with Figure 1 1 is a longitudinal section of a radial piston machine 10. The rotor 70 can be seen, which rotates with the drive shaft 30 about the rotation axis 13. The shaft section 33 of the drive shaft 30 is currently connected to the rotor 70 in a rotationally fixed manner about the rotation axis 13 via a splined shaft engagement.

[0028] The drive shaft 30 is supported on the housing 20 rotatably about the rotation axis 13 by means of first and second rotary bearings 31; 32, both of which are arranged on the same side of the rotor 70. The rotary bearings 31; 32 are designed in this case as tapered roller bearings, wherein their inner rings are respectively accommodated on the shaft section 33 of the drive shaft 30 and the outer rings are respectively accommodated inside the second ring section 25 of the third housing part 23.

[0029] On the side of the rotor 70 facing away from the rotary bearing 31; 32, the fluid distributor 24 is accommodated in a rotationally fixed manner in the housing 20, in particular in the first housing part 21. The fluid distributor 24 is preferably configured so that the hydraulic pressure acting inside it presses the fluid distributor 24 toward the rotor 70, wherein the rotor 70 in turn rests on the second rotary bearing 32 to support the corresponding force.

[0030] Nine identical pistons 71 are currently accommodated in the rotor 70, which can move linearly radially about the rotation axis 13, wherein they, together with the rotor 70, limit a working chamber 72 with a variable volume. Each piston 70 preferably includes a rotatable roller 73, which is configured as a substantially cylindrical roller, wherein the roller is most preferably supported hydrostatically on the piston 71. During operation, the roller 73 abuts against the control surface 26 of the second housing part 22. The control surface 26 extends around the rotation axis at a variable distance. The direction of the control surface 26 has six distance maxima and six distance minimums in this article in a sinusoidal shape. In this article, when the rotor 70 rotates a full circle, the piston 71 performs six reciprocating movements. It goes without saying that the number of pistons 71 and the number of reciprocating movements per revolution of the rotor are selected according to different needs.

[0031] Each working chamber 72 has a first control opening on the rotor 70 that is open to the fluid distributor 24, wherein the first control openings are arranged on a common pitch circle. The fluid distributor 24 has a total of twelve second control openings in this article, which are arranged on the same pitch circle so that they can be brought into overlap with the first control openings. There are two second control openings for each reciprocating movement of the piston 71 when the rotor 70 rotates a full circle. When the radial piston machine 10 is running at its maximum displacement, the second control openings are connected to the first and second working interfaces 11; 12 alternately along the circumference. Some or all of the second control openings can be temporarily closed by means of a valve unit to reduce the effective displacement of the radial piston machine 10 relative to the maximum displacement or completely reduce it to zero, wherein the rotor 70 rotates freely in the latter case.

[0032] At the end facing away from the fluid distributor 24, the solid shaft section 33 of the drive shaft 30 is integrally connected to the first ring section 35 of the drive shaft 30 via the disk section 34. The shaft section 33 surrounding the first ring section 35 is annular, wherein a brake disk assembly 50 of a multi-disk brake 57 is arranged inside the first ring section 35. The second ring section 25 fixedly connected to the housing 20 extends into the first ring section 35 in sections, so that the brake disk assembly 50 is arranged around the second ring section 25 on the outside.

[0033] The brake disc assembly 50 comprises a plurality of first and second brake discs 51; 52, which are arranged alternately side by side along the rotation axis 13. The first brake disc 51 is connected to the first ring segment 35 in a rotationally fixed manner. For this purpose, the first ring segment 35 has a plurality of grooves extending parallel to the rotation axis 13 on its inner circumference, into which the continuation of the first brake disc 51 is respectively embedded in a form-locking manner. The second ring segment 25 has similar grooves extending parallel to the rotation axis 13 on its outer circumference, wherein the continuation of the second brake disc 52 is respectively embedded in these grooves in a form-locking manner. The grooves are preferably arranged uniformly distributed around the rotation axis 13.

[0034] A feature of the present invention is that the brake disc assembly 50 is arranged inside the brake chamber 58. Therefore, the first and second ring segments 35; 25 each delimit the brake chamber 58 in sections. A brake piston 54 is arranged between the brake disc assembly 50 and the disc segment 34, which is movable in the direction of the rotation axis 13 and extends annularly around the rotation axis 13. The brake piston also delimits the brake chamber 58. The spring 53 for prestressing the multi-disk brake to the closed state is again arranged between the brake piston 54 and the disc segment 34. The spring 53 is preferably constructed as a single butterfly spring. It is conceivable that the spring includes a plurality of helical springs, which are arranged evenly distributed around the rotation axis 13.

[0035] It is also worth noting the inner chamber 27 of the housing 20. The inner chamber 27 is defined as a chamber inside the housing 20 which is permanently and fluidically connected with a low flow resistance to the leakage connection 14. The inner chamber 27 is partially or completely filled with pressurized fluid during the operation of the radial piston machine 10, wherein the filling is mainly caused by unavoidable leakage at various locations of the radial piston machine 10. The leakage is preferably discharged via the leakage connection 14 into a substantially pressureless tank.

[0036] Figure 3 In the area of ​​the multi-disk brake 57, Figure 2 The design of the brake chamber 58 explained above results in it being delimited by surfaces which, during operation of the radial piston machine 10, are relative to one another with respect to the axis of rotation ( Figure 2 13) rotation. The design of EP 2841763B1 just avoids this situation. Therefore, the design of the first and fourth sealing rings 41; 42 is crucial to the function of the multi-disk brake 57, because on the one hand they must withstand the pressure in the brake chamber 58, and on the other hand they must withstand the wear caused by the above-mentioned rotation movement for a long time.

[0037] The first and fourth sealing rings 41; 42 are therefore designed so that they seal the brake chamber 58 directly, wherein a leakage flow is or can be obtained at the sealing joint when the brake chamber is under pressure. It should be noted in this context that the brake pressure for the radial piston machine 10 in this context is usually provided by a hydraulic pump, which can easily replace the leakage device. It goes without saying that the leakage flow is designed to be so small that the brake pressure required for release can be generated in the brake chamber. However, at the same time, the leakage flow is designed to be so large that it causes a hydrostatic lubricating film in the sealing contact, which greatly reduces the wear that occurs there.

[0038] In both sealing cases, the leakage flow is introduced into the interior 27 of the housing 20 so that it can flow through the leakage connection ( Figure 2 14) guides the leakage flow away from the radial piston machine 20. Therefore, the fourth sealing ring 44 is arranged between the shaft section 33 of the drive shaft 30 and the second ring section 25, because it is directly adjacent to the inner chamber 27 there, so that no other measures for guiding the leakage flow are required. The leakage flow also improves the lubrication of the first rotary bearing 31 arranged there. The fourth sealing ring 44 is accommodated in the present invention in a groove in the shaft section 33, wherein the fourth sealing ring is relative to the second ring section 25 about the axis of rotation ( Figure 2 13) is a cylindrical inner circumferential surface seal.

[0039] In contrast, the sealing in the region of the first sealing ring 41 is much more complex, since there is the risk that the expected leakage flow will reach the surroundings of the radial piston machine via the gap in the region of the labyrinth seal 40 between the drive shaft 30 and the housing 20. It is therefore necessary to achieve a completely tight seal there. It should also be taken into account that a multi-disk brake must be able to be mounted.

[0040] First, it is decided to implement the drive shaft 30 with the shaft section 33, the disk section 34 and the first ring section 35 as one piece, so that the second flange ( Figure 1 The force on the radial piston machine 10 can be transmitted to the first flange (16) without elastic deformation as much as possible. Figure 1 15) and vice versa. The annular brake piston 54 rests only on the integral drive shaft 30 on the inner side 81 and the outer side 80, so that the sealing principle of the brake piston 54 known from EP 2841763 B1 can be used unchanged. The sixth sealing ring 46, for example in the form of an O-ring, is accommodated in the corresponding annular circumferential groove, which is preferably protected against wear by a harder sliding ring in the area of ​​the sealing contact.

[0041] In order to be able Figure 3In the figure, starting from the right, the spring 53, the brake piston 54 and the brake disc assembly 50 are assembled, and a separate closing ring 55 is provided, which is fastened to the inside of the first ring section 35 by means of a securing ring 56. The securing ring 56 first transmits the rotation axis ( Figure 2 13) in the direction of the force, which is caused by the spring 53 and / or by the pressure in the brake chamber 58. In addition, the securing ring also allows the closure ring 55 to rotate with the drive shaft 30 during operation of the radial piston machine 10. The fifth sealing ring 45 is accommodated in the groove on the outside of the closure ring 55, which is designed as a simple O-ring, for example, because only a static seal is required there without any problems.

[0042] The first sealing ring 41 mentioned above is accommodated in a groove on the inner circumference of the closing ring 55, wherein it is located relative to the second ring segment 35 about the rotation axis ( Figure 2 13) is a cylindrical surface seal. The leakage flow there is through the second fluid channel ( Figure 2 62) is introduced into the inner chamber 27 of the housing 20. The second fluid channel ( Figure 2 62) is implemented as a straight hole, which is about the rotation axis ( Figure 2 13) radially penetrates the second ring segment 25, wherein the second fluid channel opens on the outside into a leakage chamber 47, which is bounded by the first and second sealing rings 41; 42. Therefore, the negative pressure of the inner chamber 27 exists in the leakage chamber 47. The second sealing ring 42 is therefore only loaded with a very small pressure, wherein the second sealing ring is configured, for example, as a radial shaft sealing ring, which is relative to the second ring segment 25 about the rotation axis ( Figure 2 13) in the cylindrical surface seal. This sealing ring is completely sealed, wherein this sealing ring permanently absorbs the rotational movement of the sealing joint. However, it is particularly sensitive to particles penetrating from the outside.

[0043] The radial piston machine in this context is used, for example, for construction machinery, so that sand and / or mud are expected to act on the radial piston machine 10 from the outside. In order to make it more difficult for the corresponding particles to penetrate from the outside, a labyrinth seal 40 is first arranged between the free end face of the first ring section 35 and the housing 20. The corresponding sealing gap is preferably designed so that particles can more easily reach the outside of the radial piston machine 10 from the inside of the radial piston machine 10 than vice versa. First, a third sealing ring 43 is arranged, which is accommodated on the end face of the closing ring 55, wherein its rubber sealing lip 48 is perpendicular to the rotation axis ( Figure 2 The rubber sealing lip 48 is protected against the particles by a sheet metal ring 49. The sheet metal ring 49 preferably carries the rubber sealing lip 48, wherein its free end is embedded in a groove in the housing 20, thereby obtaining another sealing labyrinth.

[0044] The spring 53 is constructed as a disc spring in this article, which is accommodated in a spring chamber 82 between the drive shaft 30 and the brake piston 54. If there is no first fluid channel ( Figure 2 61), the spring chamber 82 will be almost completely sealed. Unavoidable leakage to the spring chamber 82 may cause the intended movement of the brake piston 54 to be hindered. This will be through the first fluid channel ( Figure 2 61) in can be reliably prevented.

[0045] Also note that the third fluid channel 63 (see also Figure 2 ), which permanently connects the brake chamber 68 to the brake interface ( Figure 2 The third fluid channel 63 is here composed of two straight holes, which extend completely in the third housing part 23 .

[0046] Reference numerals list

[0047] 10 Radial piston machine

[0048] 11First working interface

[0049] 12 Second working interface

[0050] 13 Rotation axis

[0051] 14 Leakage interface

[0052] 15First fastening flange

[0053] 16 Second fastening flange

[0054] 17 Brake interface

[0055] 20 Shell

[0056] 21 first housing part

[0057] 22 Second housing part

[0058] 23 Third housing part

[0059] 24 Fluid Dispenser

[0060] 25 Second ring segment

[0061] 26 Control Surface

[0062] 27Inner chamber of the shell

[0063] 30 Drive shaft

[0064] 31First rotary bearing

[0065] 32 Second rotating bearing

[0066] 33 axis section

[0067] 34 disk segments

[0068] 35 first ring section

[0069] 40 Labyrinth seal

[0070] 41 first sealing ring

[0071] 42 second sealing ring

[0072] 43 third sealing ring

[0073] 44 fourth sealing ring

[0074] 45 Fifth sealing ring

[0075] 46 Sixth sealing ring

[0076] 47 Leakage Room

[0077] 48 Rubber sealing lip of the third sealing ring

[0078] 49Metal plate ring of the third sealing ring

[0079] 50 brake disc assembly

[0080] 51 First brake disc

[0081] 52 Second brake disc

[0082] 53 Spring

[0083] 54 brake piston

[0084] 55 closed loop

[0085] 56 safety ring

[0086] 57 Multi-disc brake

[0087] 58 brake chamber

[0088] 61 first fluid channel

[0089] 62 Second fluid channel

[0090] 63 Third fluid channel

[0091] 70 rotor

[0092] 71 Piston

[0093] Studio 72

[0094] 73 Roller

[0095] 80 The radial outer circumference of the brake piston

[0096] 81 Radial inner circumferential surface of the brake piston

[0097] 82 Spring Chamber

Claims

1. A radial piston machine (10) having a housing (20) with a first and a second working interface (11; 12), wherein: A drive shaft (30) having at least one rotary bearing (31; 32) is rotatably supported in the housing (20) about a rotation axis (13), wherein the drive shaft (30) is connected to a rotor (70) in a rotationally fixed manner about the rotation axis (13), wherein a plurality of pistons (71) are accommodated in the rotor (70), the pistons being able to move radially about the rotation axis (13) so that the pistons and the rotor (70) respectively delimit an associated working chamber (72), wherein a control surface (26) is arranged on the inner side of the housing (20), the control surface annularly surrounding the rotor The invention relates to a housing (20) comprising a control surface (26) and a rotation axis (13), wherein the distance between the control surface (26) and the rotation axis (13) is variable along the circumference of the control surface (26), so that when the rotor (70) rotates about the rotation axis (13) so that a piston (71) contacts the control surface (72), the volume of the associated working chamber (72) changes periodically, wherein the housing (20) comprises a fluid distributor (24), which cooperates with the rotor (70) so that the working chamber (72) can alternately contact the control surface (72) when the rotor (70) rotates about the rotation axis (13). The first and second working interfaces (11; 12) are fluidically connected, wherein the drive shaft (30) comprises a shaft section (33), a disk section (34) and a first ring section (35) which are fixedly connected to each other, wherein the housing (20) comprises a second ring section (25) which is at least partially arranged inside the first ring section (35), wherein a brake disk assembly (50) is arranged radially between the first and second ring sections (35; 25) with respect to the rotation axis (13), the brake disk assembly having a plurality of individual brake disks (51; 52), wherein the brake disks (51 ; 52) are alternately connected to the first or the second annular segment (35; 25) in a rotationally fixed manner, thereby obtaining a multi-disk brake (57), wherein the brake disk assembly (50) is preloaded into the closed state of the multi-disk brake (57) by means of a spring (53), wherein an annular brake piston (54) is provided, which delimits a brake chamber (58) in sections, wherein the brake piston (54) acts together with the brake disk assembly (50) and the spring (53) so that the multi-disk brake (57) can be brought into the open state by pressurizing the brake chamber (58), It is characterized in that the brake disc assembly (50) is arranged inside the brake chamber (58), wherein the first and the second ring segments (35; 25) respectively limit the brake chamber (58) in sections, wherein the disc segment (34), the spring (53), the brake piston (54) and the brake disc assembly (50) are arranged side by side along the rotation axis (13) in a specified order so that the force of the spring (53) can be transmitted to the brake disc assembly (50).

2. The radial piston machine (10) according to claim 1, in, The brake piston (54) bears sealingly against the first ring section (35) with a radial outer circumferential surface (80), and the brake piston bears sealingly against the shaft section (33) with a radial inner circumferential surface (81), so that the drive shaft (30) and the brake piston (54) surround a delimited spring chamber (82) in which the spring (53) is arranged.

3. The radial piston machine (10) according to claim 2, in, A first fluid channel (61) is provided, which extends from the spring chamber (82) to an interior chamber (27) of the housing (20) completely within the drive shaft (30).

4. A radial piston machine (10) according to any one of the preceding claims, in, A separate closed ring (55) is provided, which is arranged radially between the first and second ring sections (35; 25) with respect to the rotation axis (13), wherein the closed ring (55) limits the brake chamber (58) in sections, wherein the brake disc assembly (50) is arranged between the brake piston (54) and the closed ring (55) in the direction of the rotation axis (13) so that the force of the spring (53) can be supported on the closed ring, wherein the closed ring (55) is supported on the first ring section (35) in the direction of the rotation axis (13).

5. The radial piston machine (10) according to claim 4, in, The closing ring (55) is supported on the first ring section (35) in the direction of the rotation axis (13) by means of a separate securing ring (56), wherein the corresponding connection is designed such that the closing ring (55) is also connected to the first ring section (35) in a rotationally fixed manner with respect to the rotation axis (13).

6. The radial piston machine (10) according to claim 4 or 5, in, The closing ring (55) is connected to the first ring section (35) on the radial outside in a rotationally fixed manner, wherein at least one dynamic sealing ring is arranged on the radial inside of the closing ring (55) between the closing ring (55) and the second ring section (25).

7. The radial piston machine (10) according to claim 6, in, The at least one dynamic sealing ring comprises a first and a second sealing ring (41; 42), wherein the first and the second sealing ring are arranged side by side in the direction of the rotation axis (13) so that a leakage chamber (47) is obtained between the first and the second sealing ring (41; 42), wherein the first sealing ring (41) directly seals the brake chamber (58), wherein the first sealing ring is constructed so that a leakage flow can be obtained at the sealing joint when the brake chamber (58) is under pressure, wherein the second sealing ring (42) is constructed to be fluid-tight, wherein the leakage chamber (47) is connected to the inner chamber (27) of the housing (20) via a second fluid channel (62).

8. A radial piston machine (10) according to any one of claims 4 to 7, in, A third sealing ring (43) is arranged between the closing ring (55) and the housing (20) in the direction of the rotation axis (13).

9. The radial piston machine according to claim 8, in, The third sealing ring (43) comprises an annular rubber sealing lip (48) which is protected by a sheet metal ring (49) against particles penetrating into the radial piston machine (10) from the outside.

10. A radial piston machine (10) according to any one of the preceding claims, in, A fourth sealing ring (44) is arranged between the shaft section (33) and the second ring section (25), which seals the brake chamber (58) in a fluid-tight manner, so that a leakage flow is obtained at the sealing joint when the brake chamber (58) is under pressure.

11. A radial piston machine (10) according to any one of the preceding claims, in, The end face of the first ring section (35) facing away from the disk section (34) cooperates with the housing (20) in the form of a labyrinth seal (40).

12. A radial piston machine (10) according to any one of the preceding claims, in, A first fastening flange (15) is arranged on the outer side of the housing (20), by means of which the radial piston machine (10) can be fastened to a superior component, wherein a brake interface (17) is arranged on the first fastening flange (15), wherein the brake interface (17) is fluidically connected to the brake chamber.

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