WO2023274847A1

WO2023274847A1 - Rotary feedthrough with fluid rotation brake

Info

Publication number: WO2023274847A1
Application number: PCT/EP2022/067228
Authority: WO
Inventors: Martin GLÜCK; Stefan Simon
Original assignee: Zf Friedrichshafen Ag
Priority date: 2021-06-30
Filing date: 2022-06-23
Publication date: 2023-01-05
Also published as: DE102021206805A1

Abstract

The invention relates to a rotary feedthrough (1) for transferring fluid between a shaft (2) and a housing (3), in which: the shaft (2) has a first mouth (7) of a first fluid conduit (6); the housing (3) has a second mouth (10) of a second fluid conduit (9); a circumferential groove (8) which connects the first mouth (7) fluidically to the second mouth (10) is provided in the shaft (2) and/or in the housing (3); and a fluid rotation brake (4, 15, 17, 29) is disposed in the groove (8) and is at least supported on the housing (3). The invention further relates to a semiannular brake component (16), a fluid rotation brake (17) composed of two semiannular brake components (16), an integral fluid rotation brake (29) and a gearbox (5) having a rotary feedthrough (1).

Description

Rotary union with fluid rotation brake

TECHNICAL AREA

The present invention relates to a rotary union for fluid transmission between a shaft and a housing, and to a semi-annular brake component, a composite fluid rotary brake, an integral fluid rotary brake, and a vehicle transmission.

TECHNICAL BACKGROUND

Rotary feedthroughs for fluid transmission between a shaft and a housing are generally known. The housing usually has an orifice which emerges radially onto the shaft and is connected to a fluid connection. Next, the shaft usually has a circumferential groove. Both the shaft and the housing often have a circumferential groove. Thus, a continuous fluid connection between the mouth of the shaft and the connection of the housing can be ensured at any angle of rotation of the shaft.

When the shaft rotates, a fluid is moved in the shaft, in particular near the orifice, and also in the groove in the circumferential direction by means of thrust forces. Therefore the fluid experiences a centrifugal force and it is pressed radially outwards. If you want to pump the fluid from radially outside to radially inside, this pressure has to be overcome. This additional pressure has to be generated in a pump, which costs energy.

There is therefore the task of providing an energy-efficient rotary feedthrough.

There is also the task of providing parts for an energy-efficient rotary feedthrough.

In addition, there is a desire that the rotary union and the parts can be used in a wide temperature range, and / or that Rotary union and / or the parts are mounted for it with little effort. Finally, it is desired that the rotary union and the parts for it meet the general requirements for transmission components and/or vehicle components, in particular for motor vehicle drive train components.

SUMMARY

According to a first aspect, the present invention provides a rotary union for fluid transmission between a shaft and a housing, the shaft having a first opening of a first fluid line, the housing having a second opening of a second fluid line, wherein in the shaft and/or in there is a circumferential groove in said housing fluidly connecting said first port to said second port, and wherein a fluid rotary brake is disposed in said groove and at least supported on said housing.

The term "rotary leadthrough" therefore designates a device or a system or an assembly comprising at least the two components shaft and housing. The device can contain further parts, such as the fluid rotation brake as a separately manufactured component or separately manufactured assembly, one or typically two or even more seals, and/or a rotary bushing.

In a narrow sense, the shaft designates a body that can rotate about its reference axis and the housing designates a stationary body. In a broader sense, the terms shaft and housing can designate two bodies between which there can be a speed difference. In particular, the housing can be a hollow shaft accommodating the shaft.

The reference axis is a line defined by the shaft and a rotatability of the shaft. In this description, terms such as "axial", "longitudinal direction", "radial", "tangential", "circumferential", "circumferential direction" and the like should refer to this reference axis in case of doubt. Typically, the first fluid line in the shaft exits the shaft in a single first port, but there may be a plurality of first ports. A "plurality" means "at least two". Preferred examples are two, three or four first orifices. Preferably, the first orifices are distributed approximately evenly, such as at equal angles, along the surface of the shaft. The second fluid line in the housing usually also exits the housing in a single second port. But there can also be a large number of second openings. Preferred examples are two, three or four second orifices. Preferably, the second orifices are distributed approximately evenly, such as at equal angles, along the housing surface. The groove is a circumferential recess in the shaft and/or in the housing. By means of the groove, the first and the second opening are in constant fluid communication with one another, independently of a rotation angle of the shaft relative to the housing, so that fluid pulsation is at least inhibited. If the groove is formed in the housing, a notch effect in the shaft can be avoided. If the groove is formed proportionally in the housing and in the shaft, installation space can be used particularly efficiently. Preferably, therefore, the groove is only formed in the shaft.

The term “rotational fluid brake” refers to a component or assembly. That the rotary fluid brake is “at least supported” on the housing means that there is at least one of a loose frictional connection, a tight frictional connection, a positive connection and/or a material connection between the fluid rotation brake and the housing. Thus, a co-rotation of the rotary fluid brake with the shaft is inhibited and preferably prevented. The fact that the rotary fluid brake is arranged in the groove means that the rotary fluid brake at least reduces a cross section of the groove. By locating the fluid rotation brake in the groove and supporting it on the housing, rotation of a fluid in the groove around the shaft is at least impeded. This reduces the speed of the fluid in the circumferential direction, so that less or no centrifugal force acts on the fluid in the groove, so that the fluid in the groove is not pressed radially outwards, so that the fluid is conveyed from radially outwards to radially less pressure has to be present inside, so that a pump pressurizing the fluid can be operated more efficiently.

The fluid should in particular be an oil, such as a mineral oil, a synthetic oil, a lubricating oil, a cooling oil and/or a hydraulic oil.

The fluid rotation brake can also be made in one piece with the housing. This can be implemented inexpensively and with high strength, for example, in the case of a molded housing, such as a cast part, sintered part or 3D printed part.

An embodiment that can be implemented easily contains a part or an assembly as a fluid rotation brake, which protrudes into the groove, penetrating the housing. For this purpose, an existing construction can be adapted with little effort by adding the penetration, such as a drill hole. For example, a standard component such as a screw, bolt, cone, nail, pin or the like can be used as the fluid rotation brake at low cost.

In an operating position, i.e. after running-in, the rotary fluid brake preferably does not bear against the shaft in order to reduce or avoid pressure pulsation.

In one aspect, the invention provides a semi-annular braking component for a rotary fluid brake. The braking component is provided with a base body which extends in a semi-annular shape about a reference axis and with at least one flow braking surface which is defined by the base body and which at least partially extends transversely to a circumferential direction with respect to the reference axis.

The ring shape of the brake component defines the reference axis to which information such as "circumferential direction" and the like refer. The fact that the flow braking surface extends “at least partially transversely to a circumferential direction” means that the flow braking surface can be a flat or curved surface. This area has at least a portion whose Surface normal is not perpendicular to the circumferential direction. For example, the flow braking surface can extend radially or approximately radially, be wedge-shaped or rounded. Because the flow braking surface is defined by the base body and extends at least partially transversely to the circumferential direction, rotation of a fluid in a groove into which the braking component can be introduced is at least impeded. Ultimately, a pump can be operated more efficiently again.

In another aspect, the invention provides a semi-annular braking component for a rotary fluid brake. The brake member is provided with a base extending in a semi-annular shape around a reference axis, and two side walls extending radially outward from both axial ends of the base.

The ring shape of the brake component defines the reference axis to which information such as "circumferential direction" and the like refer. If the brake component is cut radially, the result is a U-shaped cross section that opens radially outward. If this brake component is introduced into a groove in a shaft, the base body and the walls are located between the base and the walls of the groove on the one hand and a fluid located in the groove on the other hand. As a result, the braking member prevents shear force transmission from the bottom and walls of the groove to the fluid therein. Therefore, rotation of the fluid in the groove is at least impeded. Ultimately, a pump can be operated more efficiently again.

Of course, a semi-annular brake component for a rotary fluid brake with a base body, which extends in a semi-annular shape around a reference axis, and with at least one flow braking surface, which is defined by the base body and which extends at least partially transversely to a circumferential direction with respect to the reference axis, can also have two Be provided with side walls extending radially outward from both axial ends of the body. The semi-annular braking component can be provided with a fastening contour which is prepared for clamping and/or latching fastening of an opposite semi-annular braking component. In this way, two semi-annular brake components can be assembled in a mechanically simple manner, quickly and preferably without tools, to form an annular fluid rotary brake. A strength of the rotary fluid brake can be increased by providing such a fastening contour on each of the two ends of the semi-annular base body. In order to reduce the number of variants, the two fastening contours of a component can be designed to be opposite to one another, so that two identical parts can be fixed to one another rotated by 180°. “Opposite” is to be understood to mean contours that are prepared to rest against one another in a force-fitting and/or form-fitting manner. In other words, complementary contours should be considered, such as an edge and a locking spring, or such as a cone and a tapered hole of approximately the same angle, or such as a wedge and a counter-wedge of approximately the same angle.

In a further aspect, the invention provides a rotary fluid brake composed of two of the semi-annular brake members joined to form an annulus. This fluid rotary brake has the positive characteristics of the brake parts.

In another aspect, the invention provides a one-piece rotary fluid brake. The rotary fluid brake is provided with a main body which extends annularly around a reference axis and with at least one flow braking surface which is defined by the main body and which at least partially extends transversely to a circumferential direction with respect to the reference axis.

The one-piece rotary fluid brake is characterized by less assembly work and a lower number of parts compared to the composite rotary fluid brake. In addition, the one-piece rotary fluid brake that can be used in a groove of a shaft and/or a housing can be the flow braking surface at least inhibit rotation of a fluid around the shaft, so that ultimately a pump can be operated efficiently.

In addition, at least one retaining contour can be formed both on the brake components and on the assembled rotary fluid brake as well as on the one-piece rotary fluid brake, which is fixed to the base body and protrudes outwards from the base body. By means of the retaining contour, co-rotation of the rotary fluid brake can be prevented in a form-fitting manner by engaging in the housing. Thus, co-rotation of the fluid can be prevented with greater reliability. Thus, a pump can be reliably operated more efficiently.

Different materials can advantageously be used for the brake parts or fluid rotary brakes. Plastics have the advantages, for example, that a light fluid rotation brake can be obtained because of the comparatively low density, that chip formation is unlikely when pressed in because of the comparatively low hardness, and/or that bending open for assembly requires little force because of the comparatively high elasticity. Metals have the advantages, for example, that when a metal housing is present, because of the similar coefficient of thermal expansion, an interference fit is maintained over a wide temperature range and/or that there is high strength.

According to a further aspect, the invention provides a vehicle transmission which includes a rotary union as described above. Thus, the vehicle transmission can be operated efficiently. The vehicle transmission may include a pump configured to deliver and pressurize a fluid and fluidly connected to one of the ports. Furthermore, the vehicle transmission can also contain a fluid consumer, which is set up to be actuated fluidically and which is fluidly connected to the other orifice. According to a further aspect, the invention provides an assembly method for assembling a rotary union, as described above, for example, with the steps: providing two semi-annular brake components, connecting the two semi-annular brake components to form an annular fluid rotation brake in the groove of the shaft, and inserting the Shaft and the fluid rotation brake in the housing.

According to a further aspect, the invention provides an assembly method for assembling a rotary union, as described above, for example, with the steps of providing a one-piece rotary fluid brake, elastically bending open the rotary fluid brake, arranging the rotary fluid brake in the groove of the shaft, and inserting the shaft and the rotary fluid brake into the housing.

The two assembly methods described above and which can be claimed independently each provide a rotary leadthrough according to the invention. Both assembly methods according to the invention thus lead to a rotary feedthrough with which a pump can ultimately be operated efficiently.

Further aspects and features of the present invention result from the dependent claims, the accompanying drawing and the following description of preferred embodiments.

FIGURE LIST

Embodiments will now be described by way of example and with reference to the accompanying drawings. It shows:

1 shows a cross section through a vehicle transmission with a rotary feedthrough according to a first embodiment, with a screw being used as the rotary fluid brake, which screw passes through a housing and protrudes into a groove of a shaft;

2 shows a longitudinal section through a vehicle transmission with a rotary feedthrough according to a second embodiment, a fluid rotary brake composed of two semi-annular brake components being used; FIG. 3 is a side view of the rotary fluid brake of FIG. 2;

FIG. 4 shows a cross-section of the rotary fluid brake of FIG. 2;

FIG. 5 is a perspective view of the rotary fluid brake of FIG. 2;

6 shows a longitudinal section through a vehicle transmission with a rotary feedthrough according to a third embodiment, a fluid rotary brake composed of two semi-annular brake components being used;

FIG. 7 is a side view of the rotary fluid brake of FIG. 6;

FIG. 8 shows a cross-section of the rotary fluid brake of FIG. 6;

FIG. 9 is a perspective view of the rotary fluid brake of FIG. 6;

10 shows a longitudinal section through a vehicle transmission with a rotary union according to a fourth embodiment, wherein a one-piece rotary fluid brake is used;

FIG. 11 is a side view of the rotary fluid brake of FIG. 10;

FIG. 12 shows a cross-section of the rotary fluid brake of FIG. 10;

FIG. 13 is a perspective view of the rotary fluid brake of FIG. 10;

14 shows a longitudinal section through a vehicle transmission with a rotary union according to a fifth embodiment, wherein a one-piece rotary fluid brake is used;

FIG. 15 is a side view of the rotary fluid brake of FIG. 14; FIG. 16 is a cross section of the rotary fluid brake of FIG. 14; and FIG. 17 is a perspective view of the rotary fluid brake of FIG. 14. DESCRIPTION OF EMBODIMENTS

1 shows a first embodiment of the invention. A rotary union 1 is formed by a shaft 2, a housing 3 and a rotary fluid brake 4.

The shaft 2 is rotationally symmetrical to a reference axis A. The rotary feedthrough 1 is part of a transmission 5, which is a hybrid vehicle transmission.

In this embodiment, the shaft 2 is a hollow shaft with a first fluid line 6 which, according to an embodiment preferred for balancing, runs centrally through the shaft 2 . The fluid line 6 is fluidly connected to a plurality of first orifices 7 with a groove 8 . The groove 8 is formed in the shaft 2 as a peripheral recess. The first orifices 7 open into the groove 8, i.e. they open into the groove 8. In this embodiment, the first orifices 7 open into the bottom of the groove 8.

The housing 3 encloses the shaft 2 in the area of the rotary feedthrough 1. A second fluid line 9 runs in the housing 3 to a second orifice 10. In this embodiment, the second orifice 10 opens with a crescent-shaped cross section 11 towards the shaft 2. The groove 8 overlaps with the second muzzle 10

A cylindrical hole 12, such as a bore, is formed in the housing 3, and the shaft 2 is received in the hole. In this embodiment, the housing 3 includes a rotary bushing 13, which is a separate, in this case thin-walled component. Fluid passages 33 are present in the rotary feedthrough sleeve 13 and overlap with the second orifice 10 or the second orifices 10 . The swivel sleeve 13 is fitted into the hole 12 and it improves the friction and/or sealing properties to the shaft 2. In the first embodiment, the housing 3 is penetrated by a bore 14 in the area of the groove 8 . The bore 14 opens into the groove 8. The bore 14 is internally threaded and a screw 15 is screwed into the bore 14. The screw 15 projects into the groove 8 . Thus, in the first embodiment, the screw 15 forms the fluid rotation brake 4.

In operation, the housing 3 is stationary and the shaft 2 rotates clockwise around the reference axis A as viewed in FIG first embodiment is a gear oil. The rotation of the shaft 2 transmits a thrust force to the fluid, and the fluid is thus set in motion. The fluid rotation brake 4 in turn brakes the majority of the fluid flow in the direction of rotation or it inhibits an increase in the speed of the fluid in the direction of rotation. Thus, the fluid does not receive a high flow speed in the direction of rotation. There is no centrifugal force-induced pressure gradient between radially inside and radially outside in the groove 8 . Therefore, a pump can press the fluid from the second fluid line 9 into the groove 8 and further into the first fluid line 6 relatively easily.

In the first embodiment, only a single screw 15 acts as the fluid rotation brake 4. Here, since the screw 15 is located in front of the second port 10 in the direction of rotation of the shaft 2, the braking effect in the critical space is pronounced at the second port 10. In this embodiment, the rotary fluid brake 4 is about 1/3 turn, ie about 120 °, in front of the second mouth 10. In a non-illustrated variation of the first embodiment, which otherwise does not differ from the first embodiment, the rotary fluid brake 4 up to 90°, preferably up to 60° and more preferably even up to 30° in front of the mouth 10.

In a further embodiment that is not shown, a plurality of screws 15 are provided which protrude through the housing 3 into the groove 8 . The Figs. 2 to 5 show a second embodiment of the invention. The differences from the first embodiment are described below. The rotary fluid brake 4 according to the second embodiment is a rotary fluid brake 17 composed of two semi-annular brake components 16.

The two semi-annular components 16 extend in the form of a semi-annulus around the reference axis A and thus form a ring or semi-annulus. They each have a base body 18, which is located radially on the inside of the ring, and two side walls 19, which adjoin the base body 18 axially at the front and rear. In this respect, the component 16 corresponds to a “U” which is open to the outside and which is rotated about the axis A by approximately 180°.

The base body 18 has a plurality of openings 20 passing through it. In addition, transverse walls 21 are formed in each case, which protrude from the respective base body 18 and are connected to both side walls 19 in this embodiment. The transverse walls 21 additionally stiffen the construction, so that a thin wall thickness with an overall low weight is achieved. In relation to the reference axis A, the transverse walls 21 preferably have a smaller outer diameter than the side walls 19 in order to enable a compensating flow in the rotary fluid brake 4, 17.

End walls 22 are arranged at the respective ends of the semi-annular components 16 in the circumferential direction. These end walls 22 are connected to the respective base body 18 and the respective side walls 19 . In this embodiment, each semi-annular member 16 has an end wall 22a with a hole 23a at one end and an end wall 22b with a mushroom-shaped projection 23b at the other end. The projection 23b is opposite to the hole 23a, so that both together can form a detent. Specifically, this can mean that an outer diameter of a shank of the projection 23b preferably corresponds to an inner diameter of the hole 23a and a length of the shank corresponds to a length of the hole 23a with little play. The side wall 22a and the hole 23a on the one hand and the side wall 22b and the projection 23b on the other hand each form a fastening contour, which are opposite or complementary to one another.

When assembling the rotary feedthrough 1, the shaft 2, the components 16 and the rotary feedthrough sleeve 13 are provided first. Then the two components 16 are inserted into the groove 8 in the shaft 2 and pressed together so that the side walls 22, holes 23a and protrusions 23b cooperatively attach the two components 16 to each other in a snap-fit manner so that the fluid rotary brake 4 or 17 is annularly assembled.

Then the shaft 2 with the fluid rotation brake 4, 17 is inserted into the rotary bushing 13. The side walls 19 form an interference fit with the rotary feedthrough sleeve 13; thus, the rotary fluid brake 4, 17 is supported on the housing 3. During a run-in phase after assembly, the axial position of the rotary fluid brake 4, 17 can preferably be adjusted by contact forces and flow forces in such a way that the shaft 2 runs with little friction. If the shaft 2 and the rotary feedthrough sleeve 13 change their axial relative position during operation, for example due to temperature, the fluid rotation brake 4 can preferably also give way, ie it is “semi-loosely mounted”.

The openings 20 have edge surfaces or, in this embodiment, only one cylindrical edge surface each, the transverse walls 21 have side surfaces, and the end walls 22 also have side surfaces. All of these edges and side walls are flow braking surfaces 24. They are fixed to the base bodies by the two structurally identical semi-annular braking components 16 being formed in one piece. The flow braking surfaces 24 extend at least partially transversely to the circumferential direction; In this case, this means that the surfaces mentioned do not run strictly radially. In operation, the flow braking surfaces 24 brake fluid rotation about the reference axis A.

To save weight, the two semi-annular brake components 16 of this embodiment are made of a plastic suitable for use in Motor vehicle driven is suitable. They are molded parts, especially injection molded parts. Since the side surfaces of the side walls 19, the openings 20, the transverse walls 21 and the end walls 22 run perpendicularly and/or parallel to one another—ignoring demolding angles—there is a particular suitability for injection molding.

The Figs. 6 to 9 show a third embodiment of the invention. The differences from the second embodiment are described below. The rotary fluid brake 4 according to the third embodiment is a rotary fluid brake 17 composed of two semi-annular brake components 16.

In the third embodiment, too, both semi-annular components 16 of the composite rotary fluid brake 17 are structurally identical. In the third embodiment, each of the two components 16 has a lug 25 at one end in the circumferential direction and a flattened portion 26 at the other end. The lug 25 is from the base body

18 is offset radially outwards and projects in the circumferential direction over an end face 27 of the base body 18 .

The flattened area 26 follows a secant radially on the outside of the base body 18 in such a way that the flattened area 25 forms an obtuse to preferably vertical angle with an end face 28 . The flattening 26 is an optional further development which enables the lug 25 in the composite rotary fluid brake 17 to rest against the base body 18 of the other component 16 and at the same time the lug 25 to be constructed without an undercut, so that the semi-annular brake components 16 can be used to save costs only a two-part die-casting mold can be produced.

During assembly, the nose 25 of a component 16 and the two side walls act

19 of the other component 16 together as an interference fit. The nose 25 on the one hand and the two side walls 19 on the other hand are therefore attachment contours which are prepared for the clamping attachment of an opposite brake component 16 . As in the second embodiment, insertion into the rotary feedthrough sleeve then also follows in the third embodiment 13 forming an interference fit. By forming the components 16 from a metal, the composite rotary fluid brake 17 can maintain the interference fit over a wide operating temperature range. The components 16, the rotary feedthrough sleeve 13 and the housing 3 are thus formed from materials whose coefficients of expansion are suitable for maintaining a press fit in an exemplary operating temperature range of -40°C to 140°C. In this embodiment, these parts are made of aluminum alloys.

In operation, in the third embodiment, the base body 18 and the side walls 19 of the composite fluid rotary brake 17 cause rotation of the shaft 2 to be transmitted only slightly to the fluid present at the second orifice 10, so that ultimately the transmission 5 can be operated efficiently. In addition, the edges of the openings 20 and end faces of the lugs 25 are flow braking surfaces, which are defined by the base body 18 and which extend at least partially transversely to a circumferential direction, so that a fluid rotation of the shaft 2 has even less impact on the fluid present at the second orifice 10 is transmitted, so ultimately the transmission 5 can be operated even more efficiently. The rotary fluid brake 4, 17 of the third embodiment thus does not require a transverse wall 21.

The Figs. 10 to 13 show a fourth embodiment of the invention. The differences from the second embodiment are described below. The fluid rotary brake 4 according to the fourth embodiment is an integral fluid rotary brake 29.

The one-piece rotary fluid brake 4, 29 is formed from an annular base body 30, the ring being interrupted by a slot 31. Cross walls 21 protrude radially inwards from the base body 30 . In the fourth embodiment, the transverse walls 21 are all oriented radially, so that side faces of the transverse walls 21 are approximately at right angles to a circumferential direction. Openings 20 extend through the base body 30 . Edges of the openings 20 and the side surfaces of the transverse walls 21 are thus fixed in their position by the base body 30 and form flow braking surfaces 24, which at least partially extend transversely to a circumferential direction about the axis A. There is preferably at least one opening 20 between each two transverse walls 21.

Retaining projections 32 protrude radially outwards from the base body 30 . Fluid passages 33 are formed in the rotary feedthrough sleeve 13 and axially overlap with the groove 8 and the second orifice 10 . The retaining projections 32 engage in a form-fitting manner in part of the fluid passages 33 and thus determine the axial and rotational position of the fluid rotation brake 4, 29 relative to the rotary bushing 13 during operation.

For assembly, the one-piece rotary fluid brake 4 , 29 is elastically bent open so that the groove 8 can be inserted through the slot 31 . The fluid rotation brake 4, 29 is arranged in the groove 8 in this way. In a next step, the shaft 2 with the fluid rotation brake 4 , 29 arranged in the groove 8 is introduced or pushed into the rotary bushing 13 .

If the holding projections 32 do not already engage in a part of the fluid passages 33 after the insertion, a rotation of the shaft 2 during operation of the transmission 5 leads to a rotation of the fluid rotation brake 4, 29. The holding projections 32 support the fluid rotation brake 4, 29 on the rotary bushing 13, so that the retaining projections 32 rub against the rotary bushing 13, so that the fluid rotation brake 4, 29 brakes a rotation of the fluid around the shaft 2 via the flow braking surfaces 24, so that finally the transmission 5 can be operated efficiently. The rotation of the fluid rotation brake 4, 29 ends as soon as the retaining projections 32 snap into part of the fluid passages 33. After that, the rotary fluid brake 4, 29 is fixed to the housing 3, so that ultimately the transmission 5 can be operated even more efficiently. In the rotary feedthrough 1, on the one hand the openings 20 and the retaining projections 32 in the fluid rotation brake 4, 29 and on the other hand the fluid passages 33 of the rotary feedthrough sleeve 13 are preferably congruent in order to minimize an aperture effect. The holding projections 32 are therefore holding contours which are defined by the base body 30 and protrude radially outwards. According to a preferred development that is not shown, the openings 20 extend through the holding projections 32 .

The Figs. 14 to 17 show a fifth embodiment of the invention. The differences from the fourth embodiment are described below. The rotary fluid brake 4 according to the fifth embodiment is an integral rotary fluid brake 29.

Skids 34 are formed radially on the inside of the transverse walls 21 , i.e. at the edge of the respective transverse wall 21 spaced apart from the base body 30 . A skid 34 is preferably fixed to each transverse wall 21 . The runners 34 are each separated from one another by a gap 35 . In the fifth embodiment, too, it is preferred that at least one opening 20 leads to the outside between each two transverse walls 21 .

In the orientation of FIG. 16, a clockwise rotatable shaft 2 is assumed. For optimized fluid rotary braking, the gaps 35 are inclined counterclockwise radially outward. In addition, the gaps 35 open out immediately next to a transverse wall 21. A rotation of the shaft 2 therefore causes a double reversal of the direction of the fluid flow when it is pushed outwards. A build-up of fluid pressure due to centrifugal force is thus impeded or prevented, so that ultimately the transmission 5 can be operated efficiently.

Further variations and embodiments of the invention will be apparent to those skilled in the art within the scope of the claims. Features of the embodiments can also be combined in extracts. Reference sign

A reference axis

1 swivel

2 wave

3 housing

4 fluid rotation brake

5 gears

6 first fluid line

7 first mouth

8 slots

9 second fluid line

10 second mouth 11 crescent cross-section 12 hole

13 swivel sleeve

14 bore

15 screw

16 semi-annular brake component

17 composite fluid rotary brake

18 body

19 side panel

20 opening 21 bulkhead

22, 22a, 22b end wall

23a hole

23b projection

24 drag surface

25 nose

26 flattening

27 face

28 face 29 one-piece fluid rotation brake Main body slit retaining projection fluid passage

Claims

patent claims

1. Semi-annular brake component (16) for a fluid rotary brake (4, 17) with a base body (18) which extends semi-annularly around a reference axis (A) and with at least one flow braking surface (24) defined by the base body (18). and which extends at least partially transversely to a circumferential direction with respect to the reference axis (A).

2. Semi-annular brake component (16) for a fluid rotary brake (4, 17) with a base body (18) which extends semi-annularly around a reference axis (A) and with two side walls (19) extending from both axial ends of the base body ( 18) extending radially outwards.

3. Semi-annular brake component (16) according to one of claims 1 or 2, further comprising a fastening contour (22a, 23a; 22b, 23b) which is prepared for clamping and/or snap-fastening of an opposite semi-annular brake component (16).

A composite rotary fluid brake (4,17) comprising two semi-annular brake members (16) as claimed in any one of claims 1 to 3 connected to form a ring.

5. One-piece rotary fluid brake (4, 29) with a base body (30) which extends annularly around a reference axis (A) and with at least one flow braking surface (24) which is defined by the base body (30) and which extends at least partially transverse to a circumferential direction with respect to the reference axis (A).

6. Fluid rotation brake (4, 17, 29) according to claim 4 or 5, further comprising at least one retaining contour (32) which is fixed to the base body (18, 30) and which protrudes outwards from the base body (18, 30). .

7. Rotary feedthrough (1) for fluid transmission between a shaft (2) and a housing (3), the shaft (2) having a first opening (7) of a first fluid line (6) has, wherein the housing (3) has a second opening (10) of a second fluid line (9), and wherein in the shaft (2) and / or in the housing (3) there is a circumferential groove (8) which the first Mouth (7) fluidically connects to the second mouth (10), characterized in that a fluid rotation brake (4, 15, 17, 29) is arranged in the groove (8) and is at least supported on the housing (3).

8. Rotary feedthrough (1) according to claim 7, characterized in that the fluid rotation brake (4, 15) protrudes penetrating the housing into the groove (8).

9. Rotary union (1) according to claim 7, characterized in that the fluid rotation brake (4, 17, 29) corresponds to one of claims 2 to 6.

10. Vehicle transmission (5) with a rotary feedthrough (1) according to one of claims 7 to 9.