DE102014003133A1 - Bearing for a shaft, in particular in a valve unit, equipped with such a storage valve unit and method of manufacture - Google Patents

Abstract

The invention relates to storage for a shaft via at least one bearing point, in particular in a valve unit for motor vehicles with a pipe section and a valve shaft mounted on the pipe section and a valve body fastened thereon, such as a valve plate, the valve shaft being rotatable by an actuating means, and a valve unit equipped with such a bearing and a method for producing such a valve unit.

Description

The invention generally relates to the mounting of a shaft, so it is not limited to the application example described and claimed below, although it is applicable there, namely the example of a valve unit for motor vehicles, with particular advantage. The invention further relates to a method for forming such a storage. Such a valve unit may consist of a pipe section and have a valve shaft which is mounted on at least one provided on the pipe section bearing. On the valve shaft, a valve body, such as a valve plate, attached and the valve shaft is rotatable or pivotable via an actuating means.

Such devices are used in motor vehicles in particular in the intake or exhaust duct system and in the latter case z. B. in connection with cylinder deactivation, exhaust gas recirculation, used in catalytic converters or to influence the combustion or exhaust noise.

As actuating means come cables, rods or motors, such as electric motors used. In the latter case, such motors may be mounted on the pipe section and form a preassembled unit with the valve unit. The valve shaft is usually with the interposition of a clutch which may be formed as a spring element, either directly to the engine output shaft or indirectly via the output shaft of the engine downstream transmission, twisted or pivotable and thus the flow rate of the corresponding fluid controllable.

The bearing of the valve shaft can be done "flying", ie via only a single bearing, wherein the exhaust pipe to the passage of the valve shaft is provided a tightly connected to the pipe section socket in which a plain bearing sleeve is accommodated for mounting the valve shaft. Such an embodiment shows z. B. the DE 195 26 143 ,

At facilities like those by the DE 10 2009 052 423 have become known, the exhaust valve is additionally stored in a conical groove in the bearing bush opposite region within the exhaust pipe. The only storage and sealing point is designed relatively expensive.

The more exact bearings for the valve -bzw. Exhaust valve shaft, however, arise by means of two bearings with two bearings for the valve shaft, as for example by the DE 20 2008 005 992 U1 and the DE 10 2006 048 713 A1 has become known, however, require two openings in the walls of the exhaust pipe and thus two seals. In the DE 20 2008 005 992 U1 is a bearing also designed as a seal, which also still has spring means and thus designed consuming. The other bearing is surrounded by a separate bearing housing, which is gas-tight connected to the pipe section. The DE 10 2006 048 713 A1 has two spring-loaded bearings or seals. Such bearings and seals are very expensive because of their self-adjusting design

The higher the requirements for the tightness, the life and the temperature resistance and / or the larger and the faster such temperature changes occur, the larger and more expensive and thus more expensive are the expenses for the bearing points, in particular for the materials to be used and the Accuracy of fits between time and bearings and for the design of the seals.

The present invention has the object, the storage of shafts or axles, z. As for valve units for motor vehicles and thus to design such valve units, which is characterized by inexpensive and simple production, high tightness between shaft and plain bearing, long life and low cost manufacturing. In addition, the assembly should be simplified and cheapened.

This is achieved according to the present invention by the representation of a sliding bearing between the shaft and the bushing receiving the sleeve bearing sleeve, wherein the sleeve bearing sleeve is at least elastically deformed.

It may be useful and sufficient for some applications, especially in the context of an embodiment of a valve unit for motor vehicles, as in exhaust valves when the bearing sleeve is merely elastically deformed by applying an axial force on the plain bearing sleeve and possibly maintaining a minimum pressure., Already by a resulting radial expansion of the bearing in the direction radially inward toward the shaft to and radially outward in the direction of the bush can be created when selecting a suitable bearing material storage with sufficient tightness.

In other cases, however, a bearing may prove advantageous in which the bearing sleeve is permanently deformed or compressed, in the sense of forming. In other words, here a targeted change of the bearing sleeve takes place in a different geometry, beyond the elastic limit of the material used, but within the deformability and before it Slippage or separation breaks comes. This can be done in a particularly simple manner by the bearing sleeve in the bushing and the shaft in the bearing sleeve or bearing and shaft together in the socket -in-introduced and the forming of the bearing sleeve takes place within the socket. This can be done in a simple manner by applying a targeted pressure on the sleeve in the axial direction and / or by methods z. B. a plunger to a certain axial travel, wherein the degree of deformation is determined by the deformability of the bearing sleeve, the bridging differences in the diameters or volumes between the bush, bearing sleeve and shaft, the required tightness of storage, ie permissible leakage in the application of such storage or seal, for example, in a valve unit for motor vehicles, such as an exhaust flap, the required light or stiffness of the device. It may be advantageous if the sleeve is deformed between 40 and 80%, preferably between 55 and 70%, particularly preferably between 68 and 65% of its deformation capacity.

It has been found to be advantageous to use such a bearing sleeve, which at least contains porous material, in particular porous bearing material, such as graphite, especially soft graphite, where it has proved to be particularly advantageous to give the graphite body a sort of corset to the soft components give a certain hold or a certain dimensional stability. For this purpose, in particular an insert or support made of a braid, for which a fabric, a fleece or the like. Structures, z. B of wire, can be provided - or vice versa - it can be introduced into such a structure and the bearing material. The inherently unstable graphite is thereby brought into a constant shape and this composite body is, as described above, plastically deformed and this deformation by the insert or support to maintain this deformation. In the vast majority of cases, it will be expedient to carry out the deformation in a targeted way, depending on the pressure and the pressure, within such limits that disintegration, breakup or crumbling of the graphite structure is avoided.

Although such a valve unit with such formed by forming the bearing bearing with sealing function - or seal with storage function - already brings in design with only a bearing for the valve shaft significant advantages over the previously known with it, have those with two bearings, of which at least a formed according to the invention, compared to comparable according to the prior art even further advantages, in particular a simpler installation, when according to a further feature of the invention, the compressed bearing bearing point is provided on the actuating means facing side of the valve unit. It may be formed in this case, the other bearing by a sliding bearing - which also takes over the axial bearing of the shaft - and after insertion of the shaft from below, ie from the side facing away from the actuation - before or after forming the deformed storage - by sealing - soldering or the like. A sealing cap is sealed. This may be advantageous for such embodiments in which the shaft is pulled or pushed by spring means in the direction of the actuating means. On the other hand, however, can also take over the bearing formed by deforming the function of a thrust bearing, the shaft od with a molded shoulder, collar od. Like., Applied in the direction of the actuating means, can bear against an edge region or collar of the bearing sleeve in the interior of the valve unit. The shaft can also be axially supported in the outer region of the valve unit by the shaft, there od with a disc. Like. Provided, is resiliently urged against the edge region of the sliding bearing.

In individual cases, it may also be advantageous if the slide bearing is formed by the bearing sleeve beyond the plastic deformation also deformed, so the geometric shape is further destroyed, as described above.

The invention further relates to a method for producing a storage hach one of the claims and thus equipped units or units in which changed the geometric shape of the bearing body in a receptacle and in the presence of a wave, permanently deformed, so transformed, esp. Cold worked or cold reshaped or even destroyed.

Based on 1 - 3 let the invention be explained in more detail.

It shows 1 the invention in connection with an exhaust flap in view,

2 the exhaust flap in a section gem. line II-II,

3 an enlarged section III 2 before the production of the bearing according to the invention.

The exhaust flap A is shown in the form of a prefabricated unit with an exhaust pipe 1 used in an exhaust system, e.g. B. is welded. A lower and an upper bearing point 2 . 3 with bushings 2a . 3a and bearing elements received therein 4 . 5 serve for storage of Valve flap shaft 6 , Both sockets are gas-tight with the pipe 1 connected, z. B. welded.

The warehouse 4 the lower depository 2a is a plain bearing with axial bearing function, what the shaft 6 with a bunch 6a against the lower end face of the bearing 4 is applied and under the action of an axial spring force.

The lower bearing point is gastight to the outside via a lid 7 completed.

A console 8th using U-thighs 8a on the pipe 1 is welded together, serves together with a holding plate attached thereto 9 for supporting the actuating means B, here a cable. A coil spring 10 On the one hand, it supports itself with one end 10a on an upwardly directed boom 9a of the retaining plate 9 off and on the other hand with their other end 10b on a down-facing boom 12a a lower disc 12 from. The disc 12 , the rotation with the shaft 6 connected together with a disk 13 on which it is attached, the pulley for the soul of the cable B.

The feather 10 is designed to be on the shaft 6 fastened valve flap holds in an open position when the cable is released by a drive motor accordingly. In this position, the spring urges the boom 12b the disc 12 against the effective as a stop boom 9b of the retaining plate 9 , The feather 10 , a compression spring, exerts over the disc 12 , the wave 6 and the bundle provided for this purpose 6a an axial bias on the end face of the bearing element 4 out.

The open position of the panel 11 , ie the resting position, is both in 1 as well as in 2 presented in a very excellent position. According to a further feature of the invention here is the aperture 11 opposite the pipe 2 flat, so elliptical. It has a different design from the usual circular design, that is arranged horizontally in the present embodiment with the large semi-axis. Such an embodiment is particularly - but not exclusively - advantageous in the context of damper actuators that are self-locking and in which, when no energy is required for adjustment, the power supply is turned off to save energy. This drive motors can be self-locking for themselves, z. B braked or blocked od. Like. Or it may be a drive motor downstream unit, such as a transmission with self-locking, such as a worm gear, be provided in the power transmission. However, such drives have the disadvantage that in a power failure, when the panel is then just in the closed position, the same can not be moved out of this position and the engine comes to an uncontrolled halt. This can also be done when the shutter is closed - yes, because it is located directly in the hot gas flow, a faster and stronger thermal expansion than the exhaust pipe - a shock-like cooling of the exhaust pipe takes place, such as by the action of water spray and thus jamming the Aperture occurs - especially on motorcycles with catastrophic consequences.

Out 1 it can be seen that in the closed position 11a dot-dashed aperture 11 opposite the pipe 1 flatter, at least approximately elliptical, with its small semi-axis in the direction of the wave 6 , Is formed so that even with unusual actuators still a minimum throughput or targeted leakage is guaranteed. It has been found that a minimum leakage of up to 30% may be expedient, advantageously between 20-30%, more advantageously between 20 and 25%.

But this effect can also be achieved by the tube and / or the flap have a shape deviating from the circular shape and a targeted minimum leakage is provided therebetween, which is (clearly) above the resulting by the usual manufacturing tolerances column. Here, at least in the embodiments in which it can come to Klappenklemmern due to shock cooling of the exhaust pipe at thermally expanded flap, appropriate to make the gap between the pipe and flap in the areas of the aperture sufficiently large, adjacent to the shaft or the axis are. The plant of the flap on the pipe in the closed valve position can then be done by stopping the same with at least one of the shaft more distant area The design of the bearing 3 be related to the 3 that a section III of the 2 shows, explained in more detail. After inserting the shaft 6 together with the plain bearing 4 from below through the bushing 2a and with its upper portion through the bearing bush 3a and the insertion of the bearing body shown in dashed lines 5 that is relatively loose between shaft 6 and socket 3a is the same, by applying a predetermined force F z. B. compressed by means of an annular punch until it is the gray deposited form 5a has assumed and wherein a plastic material displacement is carried out and the bearing element 5 now both the wave 6 as well as the sleeve 3a seals and the shaft 6 is also stored. The degree of deformation, in addition to the pressure to be applied, is also determined by the axial travel around which the bearing sleeve is compressed by the punch, both of which must be taken into account, sufficient permanent deformation of the hereof soft graphite and with a wire mesh To ensure reinforced bearing body, without endangering the cohesion of the bearing body.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19526143 [0004]
• DE 102009052423 [0005]
• DE 202008005992 U1 [0006, 0006]
• DE 102006048713 A1 [0006, 0006]

Claims (20)

Bearing for a shaft via at least one bearing point, in particular in a valve unit for motor vehicles with a pipe section and a mounted on the pipe section valve shaft and a valve body mounted thereon, such as a valve plate, wherein the valve shaft is rotatable by an actuating means, characterized in that the Bearing is formed by means provided on the pipe section bearing receptacle, such as a socket and a recorded between this and the shaft, at least elastically deformed bearing sleeve. Valve unit, in particular according to claim 1, characterized in that the bearing sleeve is formed. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve is formed there after insertion between the bush and shaft. Valve unit, in particular according to one of the preceding claims, characterized in that the sleeve is deformed both radially outward against the bush to and radially inward on the shaft. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve is formed by applying a pressure in the axial direction thereof. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve is permanently deformed within its formability. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve is deformed between 40 to 80% of its shape-changing capacity. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve is formed between 55 and 70%, preferably between 58 and 65% of its shape-changing capacity. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve simultaneously represents the seal between the pipe section and shaft. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve consists of a porous material. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve consists of a porous bearing material. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve contains at least graphite. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve consists of soft graphite. Valve unit, in particular according to one of the preceding claims, characterized in that the bearing sleeve contains a corset. Valve unit, in particular according to one of the preceding claims, characterized in that the corset is embedded in the bearing material wire mesh. Valve unit for motor vehicles with a pipe section and a valve shaft mounted thereon via two bearing points and a valve body mounted thereon, such as a valve plate, wherein the valve shaft is rotatable by an actuating means, the bearings are formed by means of a respective pipe section attached to the bearing receptacle in the form of a socket , which each form a plain bearing and of which at least the actuating means facing a bearing bush contains, which is formed there. Valve unit, in particular according to claim 16, characterized in that the valve shaft is inserted from the side facing away from the actuating means in the bearing points. Valve unit, in particular according to claim 17, characterized in that the bearing point with the deformed bearing sleeve averted bearing point is gas-tight. A method for forming a sliding bearing for a shaft by means of a bearing sleeve accommodated in a bush, characterized in that the bearing sleeve is formed after the introduction of the same between the bush and shaft. A method for forming a sliding bearing for a shaft, in particular according to claim 19, characterized in that the bearing sleeve between 40 to 80%, preferably between 55 and 70%, particularly preferably between 58 and 65% of its deformability is converted.

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