Connecting device for supplying and / or removing a medium at a steering knuckle

Abstract

Connecting means (1) for supplying and / or conveying a medium to a steering knuckle (20), with at least one connection (3) for connecting the connecting means (1) to a source and / or a consumer (M), wherein the at least one connection (3) has a channel (4) for guiding the medium, and wherein the connecting means (1) has a cylindrical section (8) at its end facing the steering knuckle (20) and the section (8) has at least one transfer groove (9.1, 9.2) which is connected to the channel (4), and the connecting means (1) has at least one screw connection option which enables the connecting means (1) to be fastened to a steering knuckle bolt (15), characterized in that the section (8) has annular recesses (10 - 13) which are suitable for receiving corresponding seals and which are arranged immediately adjacent to the at least one transfer groove (9.1, 9.2).

Description

[0001] The invention relates to a connecting means having the features of the preamble of patent claim 1.

[0002] From the series production of commercial vehicles, it is known to equip them with auxiliary hydraulic drives if necessary. These auxiliary hydraulic drives comprise wheel hub motors, which are supplied with a hydraulic medium by the corresponding hydraulic systems of the commercial vehicles, providing a sufficient flow rate while simultaneously ensuring the required pressure.

[0003] The generic document DE 10 2009 023 418 A1 discloses an arrangement of a braking device on a steerable wheel axle of a vehicle, with a multi-disk brake running wet by means of a cooling fluid, wherein the cooling fluid can be fed in a circuit to a heat exchanger, for which purpose an inlet and an outlet are provided on the multi-disk brake, which are each connected to a line connected to the heat exchanger via a rotary coupling which can be pivoted synchronously with the steering movement.

[0004] Furthermore, DE 18 11 886 A discloses a hydrostatic vehicle drive system with at least one hydraulic drive motor which can be moved together with a vehicle wheel assigned to it and with means for conveying pressure medium to this motor, wherein a pressure medium line joint, preferably a ball joint, is provided which simultaneously forms part of a steering linkage.

[0005] In order to achieve the desired high torques for driving the wheel driven by the hydraulic auxiliary drive, very high pressures of up to 450 bar are required.

[0006] Hydraulic lines are provided to guide the hydraulic medium from the hydraulic device (source), which is particularly attached to a respective frame of the commercial vehicle, to the wheel-side wheel hub motor (consumer), which is thus movable relative to the frame and the hydraulic device.

[0007] However, since the hydraulic device for supplying the wheel hub motor with the hydraulic medium is arranged fixed to the frame, while the wheel hub motor is movable relative to the frame and thus the hydraulic device as a result of compression and rebound movements and possibly as a result of steering movements of the wheel, rotary unions are provided on a steering knuckle bearing, via which the wheel hub motor is supplied with the hydraulic medium via the hydraulic lines.

[0008] A connecting means for a rotary union on a kingpin bearing is known from DE 102011100660 A1. The connecting means has two connections. Each connection has a channel designed as a forward and return channel for the medium, in particular hydraulic oil.

[0009] To complete the rotary union, a kingpin is arranged below the connecting element. This kingpin has transfer grooves at the end facing the connecting element, which correspond to the channels of the connecting element and to the channels on the steering knuckle side, thus enabling fluid flow from the hydraulic system to the wheel hub motor and back to the hydraulic system. Seals are provided for a sealed connection from the kingpin to the steering knuckle, in particular to a steering knuckle fork. The kingpin has corresponding recesses into which the seals are inserted.

[0010] Since these seals are subject to wear, they must be replaced. This type of rotary union therefore has the disadvantage that replacing the seals is complex and expensive. Because the kingpin is pressed into the steering knuckle, replacing the seal requires disassembling the axle, as it is impossible to press out the kingpin while the axle is still installed.

[0011] The invention is therefore based on the object of providing a maintenance-friendly kingpin bearing for a vehicle axle, in particular a commercial vehicle axle.

[0012] This object is achieved by the combination of features of patent claim 1. According to the invention, the connecting means has a substantially cylindrical section at its end facing the steering knuckle, wherein the section has at least one transfer groove which is connected to the channel.

[0013] Furthermore, the connecting means has at least one screwing possibility which enables the connecting means to be fastened to a kingpin, wherein the section has annular recesses which are suitable for receiving corresponding seals and are arranged directly adjacent to the at least one transfer groove.

[0014] It is particularly advantageous that the entire rotary feedthrough of the hydraulic supply on a kingpin bearing of an axle of a motor vehicle, in particular a commercial vehicle, is made in one piece in the connecting means and the seal(s) to be replaced is / are arranged directly on the connecting means.

[0015] A further advantage of the embodiment according to the invention is that only the connecting means needs to be removed when replacing the seal, while the kingpin to be pressed out can remain in the kingpin of the axle, in particular a rigid axle. For this purpose, the connecting means is preferably connected at its connection(s) to a hydraulic line on the hydraulic device side (source-side connection) by means of a screw connection. Furthermore, the connecting means has at least one further screw connection option that enables the connecting means to be attached to the kingpin. Such a screw connection option can be made possible, for example, by a central bore that continues in the kingpin. Advantageously, such a screw connection allows the connecting means to be replaced with little effort and cost-effectively.Furthermore, the connecting means according to the invention has the advantage that the hydraulic line on the hydraulic device side, i.e., the hydraulic line leading from the source (pump) to a hydraulic wheel hub motor (consumer), can be at least partially designed as rigid piping. Preferably, the direct feed into the connecting means is designed as rigid piping, while the chassis-side hydraulic line is designed as a flexible hose line to accommodate the relative movements (spring travel) between the axle (axle body) and the chassis. Compared to a purely flexible hose line, the rigid piping has the advantage that the maintenance intervals for the rigid piping are significantly longer, and costs can be reduced accordingly.

[0016] With a steerable axle, a wheel mounted on the axle body pivots around it. A particularly advantageous feature is that the connecting element and the kingpin are rigidly connected to each other, so that the connecting element does not move relative to the axle body. This prevents the hydraulic line from twisting during a steering movement, which is the case, for example, with flexible hose lines known from the prior art.

[0017] A closed hydraulic circuit is required to operate the hydraulic wheel hub motor. For this purpose, the hydraulic medium, in particular the hydraulic oil, is pumped from the frame-side hydraulic device, in particular from a pump (source), via the connecting means to the wheel hub motor. Because the section is at least partially accommodated in a corresponding receptacle in the steering knuckle, the transfer groove is located in the outer surface of the section, and annular recesses for receiving a seal are arranged directly adjacent to the at least one transfer groove, and the at least one transfer groove is operatively connected to a channel on the steering knuckle, a rotary feedthrough on a steering knuckle pin bearing of a steerable axle is easily enabled. Thus, the hydraulic oil can be easily transferred from the pump into the steering knuckle, where it is supplied to the wheel hub motor.A further advantage is that the wheel hub motor's hydraulic supply runs within the steering knuckle or within the steering knuckle pin bearing. This arrangement reduces the risk of piping located outside the steering knuckle or kingpin bearing being damaged or even torn off during off-road driving of the commercial vehicle. Another advantage is that the hydraulic line on the hydraulic system side can be located on the upper side of an axle beam. This also reduces the risk of torn or damaged hydraulic lines, especially hydraulic lines located on the underside of the axle beam—that is, on the side of the axle beam facing the roadway.

[0018] To enable a functional rotary union on a steerable axle, particularly on a steerable front axle of a commercial vehicle, it is advantageous for the at least one transfer groove to extend in a ring shape, and for the ring-shaped extension to encompass an angle between 90° and 240°, particularly over an angle of 180°. Since the steering knuckle is pivotably mounted relative to the axle body and the connecting means is essentially rigidly attached to the hydraulic line on the hydraulic system side, the transfer groove enables a fluid connection to the steering knuckle-side channel that is relevant for all steering angles. Thus, the hydraulic wheel hub motor can be operated at any steering angle.

[0019] A further advantage is seen in the fact that the medium is preferably a hydraulic fluid. Nevertheless, the scope of the invention is not limited exclusively to a connecting means that can carry a hydraulic medium, in particular hydraulic oil, but also encompasses gaseous media, in particular compressed air. Since commercial vehicles have pneumatic systems—for example, pneumatically operated braking systems on their trailers and / or semi-trailers—it makes sense to use a pneumatic wheel hub motor as an auxiliary drive instead of a hydraulic motor.

[0020] In the following, an embodiment of the invention is explained in more detail with reference to the accompanying drawings.

[0021] Showing: Fig. 1 A lanyard in a partially sectioned side view, Fig. 2 the connecting means in a plan view of its underside, and Fig. 3 the connecting element in the installed state.

[0022] Fig. Figure 1 shows a side view of a connecting means 1 according to the invention. The connecting means 1 has a cover 2 on its head portion, from which a connection 3 extends toward a hydraulic device (source) not shown, in particular a body-mounted hydraulic pump—hereinafter referred to as the pump.

[0023] The connection 3 is preferably designed as a hollow cylindrical tube, forming a channel 4. The channel 4 serves to convey a medium, preferably a hydraulic fluid, in particular a hydraulic oil, and can be designed as a forward and / or return line for the medium. The connection 3 is designed in a stepped manner and widens toward the pump, forming a flange 5 at the end of the connection 3.

[0024] The flange 5 has at least one bore 6, in particular four bores 6, so that it can be connected to a hydraulic line on the hydraulic device side connecting the pump to the connecting means 1. The hydraulic line on the hydraulic device side is preferably designed as rigid piping, although a flexible hose line is also conceivable.

[0025] It has proven advantageous for the connection to be designed as a detachable screw connection. For this purpose, the at least one bore 6 in the flange can have an internal thread for receiving a screw bolt. Alternatively, a screw bolt can be passed through the bore 6, which engages a thread or a screw nut in the area of ​​the hydraulic line on the hydraulic system side.

[0026] A cylindrical section 8 extends along an annular underside 7 of the cover 2. This section has a smaller diameter than the cover 2. Furthermore, the section 8 has a first transfer groove 9.1 and a second transfer groove 9.2. The annular transfer grooves 9.1, 9.2 can each extend at an angle of 180°. Furthermore, the figure shows that the two transfer grooves 9.1, 9.2 are arranged in different planes of an axial extension direction R. Preferably, the transfer grooves 9.1, 9.2 are arranged at least partially overlapping in the extension direction R.

[0027] Furthermore, section 8 has annular recesses 10-13 suitable for accommodating corresponding seals. The seals can be, for example, O-rings, piston seals, or the like. The seals can be pressurized to a pressure of 450 bar.

[0028] The Fig. 2 shows the connecting element 1 formed as a cast or forged part, from below.

[0029] The cover 2 has three bores 6, which serve to fasten the connecting means 1 in a kingpin bearing 14 (not shown), in particular to a head part of a kingpin 15. Screw bolts are preferably passed through the bores 6 of the connecting means 1 and can engage in corresponding bores in the kingpin 15. The bores in the kingpin 15 preferably have an internal thread, so that the screw bolts, with their external threads, can enable a detachable screw connection.

[0030] The figure also shows a first and a second connection 3.1, 3.2 with corresponding channels 4.1, 4.2, and flanges 5.1, 5.2. In the following, connection 3.2 refers to the supply line from the pump (source) to a hydraulic wheel hub motor M (consumer), and connection 3.1 refers to the return line from the wheel hub motor M to the pump.

[0031] The first and second flanges 5.1, 5.2 are constructed as a single piece. Furthermore, a rib 16 connects the first and second connections 3.1, 3.2, further increasing the stability of the two connections 3.1, 3.2. The rib 16 is not mandatory.

[0032] The figure also shows a portion A1 of the first channel 4.1, which is formed essentially parallel to the extension direction R of section 8. This portion is formed by a bore through the solid material of section 8. Portion A1 is thus an extension of the first channel 4.1 and connects it to the first transfer groove 9.1. According to this embodiment, portion A2 connects the second channel 4.2 to the second transfer groove 9.2.

[0033] The channels 4.1 and 4.2, with their corresponding transfer grooves 9.1, 9.2, are accessed through a substantially vertical bore in a base 17 of section 8. The bores are positioned such that only one transfer groove 9.1, 9.2 is connected to its corresponding channel 4.1, 4.2. It has proven advantageous that the transfer grooves 9.1, 9.2 are only partially aligned in the direction of extension R. Furthermore, the bores are stepped. The portion of the bore facing the base 17 has a larger diameter than the portion of the bore forming sections A1, A2. The portion of the bore with the larger diameter is sealed fluid-tight or gas-tight with the transfer grooves 9.1, 9.2 after the channels 4.1, 4.2 have been accessed.For this purpose, a screw, plug or the like, with a seal if necessary, can be inserted and fixed into this part of the bore.

[0034] In addition, the connecting means 1 can have a further bore, not shown here, for a grease nipple. The grease nipple is preferably arranged laterally on the cover 2 and serves to supply a bearing element 18 of the steering knuckle bearing 14 with a lubricant, in particular a lubricating grease or oil. For this purpose, the bore extends from the cover 2 through the section 8, so that the lubricant introduced under pressure reaches the steering knuckle 15 and lubricates the bearing element 18 there. The arrangement of the grease nipple on the cover 2 is not limited to a lateral arrangement. Rather, the available installation space dictates the arrangement of the grease nipple.

[0035] The figure also discloses a centering device 19, which can be designed, for example, as a mandrel or pin and preferably serves to centrally align the connecting element 1 in a steering knuckle 20. This enables a defined annular gap between the connecting element 1 and the steering knuckle 20, so that an optimally functioning seal can be achieved. Furthermore, the centering device 19 can be inserted into a corresponding recess on the head side of the steering kingpin 15 when the connecting element 1 is installed. It is advantageous if the centering device 19, in particular the mandrel or pin, has a flat side. This enables anti-twist protection when installed, and also facilitates the alignment of the connecting element 1, since the positive connection between the centering device 19 and the corresponding recess on the steering kingpin 15 allows only one mounting position.Thus, the hole pattern of the connecting element 1 is also congruent with the hole pattern on the head side of the kingpin 15. This allows for easy alignment and screwing of the connecting element 1 to the kingpin 15. Furthermore, the connections 3.1, 3.2 are aligned in the direction of the corresponding hydraulic lines on the hydraulic system side, which also enables easy screwing of the two components.

[0036] To fix the connecting element 1 to the steering kingpin 15, several, in particular three, bores 6 are drilled into the connecting element 1. Since such bores 6 are prone to errors and complex, and also weaken the component, alternatively only one central bore can be drilled into the connecting element 1. A central bore has the advantage over multiple bores 6 that the central bore allows free, i.e. stepless, alignment of the connecting element 1 within the steering kingpin bearing 14. In this case, the centering 19 can advantageously be omitted. When the connecting element 1 is inserted into the steering kingpin bearing 14, the connecting element 1, in particular the connections 3.1, 3, 2, are brought into the intended assembly position. In a further assembly step, a screw bolt is guided through the central bore and fixed to the steering kingpin 15 according to the previous embodiment. Fig. 3 shows the connecting means 1 according to the invention in the installed state in a kingpin bearing 14.

[0037] Here, the connecting element 1 is inserted into an upper part of the steering knuckle 20, in particular into an axle fork. The upper part of the steering knuckle 20 refers to the area facing a vehicle body (not shown). Accordingly, a lower part of the steering knuckle 20 is the area facing a roadway (not shown).

[0038] The outer surface of the cylindrical section 8 of the connecting element 1 can be completely enclosed by the steering knuckle 20 when installed. Accordingly, the diameter of section 8 depends on the diameter of its receptacle in the steering knuckle 20. Furthermore, the outer surface of section 8 can also be stepped. By using seals with different diameters in a stepped design of the outer surface, the risk of damage to seals during assembly of the connecting element 1 in the steering knuckle 20 can be minimized. Furthermore, the underside 7 of the cover 2 sits slidably on a corresponding surface of the steering knuckle 20, with an annular sealing lip 21 being arranged to prevent dirt from entering the steering kingpin bearing 14.

[0039] As previously described, recesses 10 - 13 are provided between the section 8 and the steering knuckle 20, which recesses carry annular seals which seal the connecting means 1, in particular the section 8, with respect to the steering knuckle 20 and thus prevent the escape of the pressurized hydraulic oil.

[0040] The kingpin bearing 14 as such is well known from the prior art, with the kingpin 15 being arranged in the direction of the roadway and thus below the section 8. The kingpin 15 is at least partially enclosed by the upper and lower parts of the steering knuckle 20, in particular the axle fork. Furthermore, the kingpin 15 is encompassed by an axle stub 22 of an axle body (not shown). The axle body is preferably designed as a rigid axle.

[0041] To enable pivoting of the steering knuckle 20 around the axle body, in particular around the steering knuckle 22, bearing elements 18 (not shown in detail) are inserted between the steering knuckle pin 15 and the upper or lower part of the steering knuckle 20. The bearing elements can be designed as plain, rolling, and / or ball bearings. Preferably, the bearing elements 18 are designed as single-row or multi-row needle bearings. Furthermore, a thrust washer 23 with a corresponding radial shaft seal is arranged on the upper side of the steering knuckle 22, and a shim 24 with a corresponding axial bearing is arranged on the underside of the steering knuckle 22, so that the steering knuckle 20 can be arranged with a precise fit on the steering knuckle 22.

[0042] Below the kingpin 15, a cover plate 25 is inserted into the lower part of the steering knuckle 20 according to the prior art. The cover plate 25 may have a grease nipple for lubricating the lower bearing element 18.

[0043] The figure also shows a steering knuckle-side channel 26, which, viewed in the direction of extension R, extends in different planes and in the direction of the wheel hub motor M. The steering knuckle-side channel 26 also has a portion A3 running essentially perpendicular to the roadway and a portion A4 running through an axle journal 27. The portion A4 of the steering knuckle-side channel 26, which opens into a part 28 of the wheel hub motor M, can be designed as a central bore through the axle journal 27. Since the portion A3 of the steering knuckle-side channel 26 is also formed by a bore, the end opposite the portion A4 must be closed in a fluid-tight or gas-tight manner by a closure piece 30. Corresponding plugs, screw bolts, and the like can be used for this purpose, corresponding to the connecting means 1.

[0044] Furthermore, a bearing unit 31 and a bearing part 32 are arranged on the axle journal 27, which together form a wheel bearing. The bearing unit 31 is preferably designed as a rolling bearing and allows relative rotation of the bearing part 32 with respect to the axle journal 27. A brake disc 33 and a wheel hub 34 are arranged on the bearing part 32, which are thus also relatively rotatable with respect to the axle journal 27, with a vehicle wheel being fixable to the wheel hub 34.

[0045] A first part 35 of the wheel hub motor M is detachably connected to the wheel hub 34—for example, via a screw bolt—36. A second part 37 of the wheel hub motor M is also detachably connected to the axle journal 27 and / or another part of the steering knuckle 20. Because the two parts 35, 37 of the wheel hub motor M can be rotated relative to each other, the wheel hub 34 and thus the entire wheel bearing can be driven by the wheel hub motor M.

[0046] In addition, another seal (not shown) is inserted between the wheel hub 34 and the wheel hub motor M, so that a possible loss of the hydraulic medium is reliably avoided.

[0047] Preferably, the wheel hub motor M is designed as a radial piston hydraulic motor, enabling forward and reverse travel. Furthermore, the wheel hub motor M can generate different engine torques, allowing the commercial vehicle to travel at different speeds. For this purpose, the commercial vehicle can have a switching device in a driver's cab that can be operated by the vehicle driver and serves to select a gear, in particular a slow or fast gear. Alternatively, automatic selection of the gear is also conceivable.

[0048] By way of example, the figure shows the arrangement of the connecting means 1 on the upper part of the steering knuckle 20. In a further embodiment of the invention, it is also conceivable for the connecting means 1 to be arranged on the lower part of the steering knuckle 20.

[0049] Furthermore, both the upper and the lower part of the steering knuckle 20 can each have a connecting means 1. In particular, this can also represent a leakage flow in addition to the hydraulic supply of the wheel hub motor M.

[0050] Leakage flow is understood to mean that portion of the hydraulic medium that is lost due to leaks between two components from the volume flow for driving the wheel hub motor M. This leakage flow must be conveyed back to the pump via an additional line arrangement - for example, through rigid piping and / or a flexible hose line - to ensure continuous operation of the wheel hub motor M. Furthermore, the leakage flow can be enabled by attaching a line directly to the steering knuckle 20 and thus does not necessarily require a second connecting means 1.

[0051] In addition to a supply line (second connection 3.2) from the pump to the wheel hub motor M and a return line (first connection 3.1), the connecting means 1 can also have only one line 3 for the hydraulic oil, also with only one channel 4 and a transfer groove 9. Therefore, such a hydraulic piping requires two connecting means 1 to enable a hydraulic circuit between the pump and the wheel hub motor M. Advantageously, the required connecting means 1 are arranged on the upper and lower parts of the steering knuckle 20.

[0052] A hydraulic device, in particular the pump, which is arranged on the frame side of the commercial vehicle, serves to drive the wheel hub motor M. The pump, in particular a variable-displacement axial pump, preferably delivers hydraulic oil to the wheel hub motor M during operation. The pump can be connected to an oil reservoir on the frame side, which can also serve as a volume expansion tank. At least during operation of the pump, it can be operatively connected to an engine-side power take-off of the commercial vehicle via a switchable multi-plate clutch. Alternatively, it is also conceivable for the pump to be a fixed-displacement axial pump, which can be connected to a retarder of the commercial vehicle via a switchable multi-plate clutch.

[0053] The hydraulic auxiliary drive is capable of driving the commercial vehicle. Preferably, however, the hydraulic wheel hub motor M is connected to the regular main drive provided by an internal combustion engine. For this purpose, one or more vehicle wheels can have a hydraulic wheel hub motor M. The advantage of this is that a cost-effective all-wheel drive can be provided for a commercial vehicle. Such hydraulic auxiliary drives are preferably used in commercial vehicles that are primarily operated on paved roads but must also undertake temporary off-road driving.

[0054] When the hydraulic auxiliary drive—the wheel hub motor M—is activated by the driver or automatically by the commercial vehicle, the pump is activated. This pump pumps the hydraulic oil, for example, from the oil reservoir through the frame-side piping toward the wheel hub motor M.

[0055] The hydraulic oil is pumped through channel 4.2 of the connecting element 1 at a pressure of up to 450 bar. Furthermore, the medium flows via portion A2 into the transfer groove 9.2 and from there into the steering knuckle-side channel 26. The steering knuckle-side channel 26 conveys the medium via its portions A3 and A4 into the corresponding part 28 of the wheel hub motor M, where the motor is rotated by the hydraulic oil and drives the commercial vehicle.

[0056] From the wheel hub motor M, the hydraulic oil is pumped back to the pump through the return line. Fig.The hydraulic medium flows through the second steering knuckle-side channel 26 (not shown in Figure 3) and its portions A3 and A4 via the transfer groove 9.1 and the associated channel 4.1 and its portion A1 back into the hydraulic system-side piping and further to the pump or the oil reservoir upstream of the pump. Since the hydraulic oil sometimes heats up considerably during its delivery, it can be passed through an oil cooler to dissipate heat energy, for example, to the environment and / or to other components of the commercial vehicle provided for this purpose.

[0057] By reversing the flow direction of the hydraulic oil, the commercial vehicle can be driven forward and backward using the hydraulic wheel hub motor M. This can be achieved, for example, by a suitable pump that can provide both flow directions. Reverse travel is preferably achieved using a switching valve. For this purpose, the valve connects the pressure side of the pump to the return line of the hydraulic circuit and the supply line to the reservoir or the suction side of the pump.

[0058] If the wheel hub motor M is arranged on a steerable axle, in particular on a front axle of the commercial vehicle, and the driver carries out a steering movement, the steering knuckle 20 pivots relative to the axle stub 22 or relative to the steering kingpin 15. Due to the fact that the transfer groove 9.2 extends at an angle of 180°, the channel 26, with its open end, is fluidically connected to the transfer groove 9.2 with each steering angle, so that a constant fluid circuit is ensured and thus the operation of the wheel hub motor M is safely possible even during steering movements.

Claims

[1] Connecting means (1) for supplying and / or discharging a medium to a steering knuckle (20), having at least one connection (3) for connecting the connecting means (1) to a source and / or a consumer (M), wherein the at least one connection (3) has a channel (4) for guiding the medium, and wherein the connecting means (1) has a cylindrical section (8) at its end facing the steering knuckle (20), and the section (8) has at least one transfer groove (9.1, 9.2) connected to the channel (4), and the connecting means (1) has at least one screw connection option that enables the connecting means (1) to be fastened to a steering knuckle pin (15), characterized by that the section (8) has annular recesses (10 - 13) which are suitable for receiving corresponding seals and are arranged directly adjacent to the at least one transfer groove (9.1, 9.2). [2] Connecting means (1) according to claim 1, characterized by that the section (8) is at least partially received in a corresponding receptacle of the steering knuckle (20). [3] Connecting means according to one of claims 1 or 2, characterized by that at least one transfer groove (9.1, 9.2) is located in the lateral surface of the section (8). [4] Connecting means according to one of claims 1 to 3, characterized by that the at least one transfer groove (9.1, 9.2) is in operative connection with a channel (26) on the steering knuckle side. [5] Connecting means (1) according to one of claims 1 to 4, characterized by that the at least one transfer groove (9.1, 9.2) extends in a ring shape and that the ring-shaped extension comprises an angle between 90° and 240°. [6] Connecting means (1) according to one of claims 1 to 5, characterized by that the medium is a hydraulic fluid.

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