WO2013178558A1

WO2013178558A1 - Radial sliding bearing comprising a floating bush body

Info

Publication number: WO2013178558A1
Application number: PCT/EP2013/060806
Authority: WO
Inventors: Ralf Böning; Ralph-Maurice KÖMPEL; Christian Schmidt; Jürgen KROTTENTHALER; Stefan Reuter
Original assignee: Continental Automotive Gmbh
Priority date: 2012-05-29
Filing date: 2013-05-24
Publication date: 2013-12-05
Also published as: DE102012208960A1

Abstract

The invention relates to a radial bearing having a shaft mounted in a housing and a floating bush body provided between the housing and the shaft. An inner lubricating gap lies between the shaft and the floating bush body. An outer lubricating gap is formed between the housing and the floating bush body. The floating bush body is provided with an imbalance in order to counteract an imbalance of the shaft.

Description

description

The invention relates to a radial bearing which has a shaft mounted in a housing and a floating body provided between the housing and the shaft, wherein between the shaft and the Schwimmbüchsenkörper an inner lubrication gap and between the housing and the Schwimmbüchsenkörper present an outer lubrication gap.

Such radial bearings are already known. A simplified, dimensionally oversized cross-sectional representation of such a radial bearing is shown in FIG. There is between a rotating shaft 8, which rotates at a speed n _w , and a housing 10, a likewise rotating floating bush body 1, which rotates at a speed n _B , is provided. Between the housing 10 and the floating bush body 1, a lubricating oil-filled outer lubricating gap 9 is provided. Between the floating body 1 and the shaft 8 is also filled with lubricating oil inner lubricating gap 11. The outer lubricating gap 9, the lubricating oil is provided by provided in the housing 10, not shown holes. Furthermore, not shown holes are also provided in the floating body 1, through which the inner lubrication gap 11 is supplied from the outer lubricating gap 9 with lubricating oil. These lubricating oil films absorb radial forces occurring during operation.

A radial bearing equipped with a floating body has many advantages over a standing slide bearing the disadvantage that in operation when the shaft rotates at a high rotational speed, even small imbalances of the shaft instabilities of the camp have the result to complete destruction lead the camp.

In order to reduce such instabilities of the bearing, this problem is tried in practice by the best possible balancing of the shaft in the entire rotational speed range to meet the wave. However, these attempts have not yet led to the desired success, especially for the range of high rotational speeds. The object of the invention is to provide a radial bearing in which an occurrence of instabilities of the radial bearing is reduced in the entire rotational speed range of the shaft. This object is achieved by a radial bearing with the features specified in claim 1. Advantageous embodiments of the invention are specified in the dependent claims.

According to the present invention, a radial bearing having a rotatably mounted in a housing shaft and a provided between the housing and the shaft, rotatable in the housing about a rotation axis floating body, said floating body in the manner of a hollow cylinder, with an inner diameter of the shaft receives and an outer diameter for receiving in the housing, is formed and formed between the shaft and the inner diameter of the Schwimmbüchsenkörpers an inner lubricating gap and between the housing and the outer diameter of the Schwimmbüchsenkörper an outer lubricating gap, wherein the Schwimmbüchsenkörper is further designed such that it is equipped with a defined imbalance with respect to the axis of rotation of the floating body.

The imbalance refers to the axis of rotation of the

Floating bush body which is identical to the longitudinal axis of the floating bush body, which is located in the center relative to the outer diameter, and which coincides with the axis of rotation of the shaft with a concentric arrangement of the inner diameter and uniform formation of the inner lubricating gap over the circumference. The defined imbalance is determined both in terms of their location relative to the swimming pool body as well as the amount in advance. The determination of the required amount as well as the advantageous position of the unbalance can be made in advance mathematical way, by computer simulation or in appropriate test series.

The cause of an imbalance lies in an uneven mass distribution of the rotating body, here the Schwimmbüchsen- body, based on its circumference on its structurally predetermined axis of rotation. By the uneven mass distribution Enver ^¬ a positional deviation of the axis of inertia of the rotating body results in relation to its rotational axis. This positional deviation can be used as a measure of the size, ie the amount of imbalance and is also referred to as eccentricity. The eccentricity indicates the magnitude of the positional deviation of the inertial axis of a rotary body to its axis of rotation, for example in millimeters (mm). Accordingly, the radial bearing according to the invention in an advantageous embodiment is characterized in that the defined imbalance of the floating bush body, specified as eccentricity in relation to the bearing clearance of the inner lubricating gap, in a range between 15% and 35%, in particular 20% to 30% of the inner lubrication gap formed bearing clearance is.

In this case, the bearing clearance calculated as the double gap width of the inner lubricating gap with concentric arrangement of the shaft in the floating body. In a specific embodiment, there is a circumferential inner lubrication gap of 0.011 mm thus the bearing clearance is 0.022 mm. In this example, an eccentricity of 0.0033 mm to 0.0077 mm would thus be provided.

In a further advantageous embodiment, the radial bearing according to the invention is characterized in that the defined unbalance of the floating bush body, specified as eccentricity, is in a range of 0. 003 mm to 0.008 mm, in particular 0.005 mm. The ranges mentioned in the two aforementioned examples of the dimensioning of the imbalance have proven to be particularly advantageous in tests with shafts of a diameter range between 8 mm to 25 mm, since the defined imbalance on the one hand small is enough, in turn, not to negatively affect the concentricity of the overall system, on the other hand, however, is large enough to counterbalance the imbalance of the wave in the entire rotational speed range, especially in the range of high rotational speeds up to 250,000 revolutions / minute and beyond Act .

There are various possibilities for the design of the defined imbalance of the floating ^¬ bush body. Thus, the unbalance of one, two or more introduced into the floating body bumps can be formed. Alternatively, the imbalance of one or more in the

Swimming pool body introduced through holes or blind holes, an inserted into the floating sleeve body inner groove or be formed by a deformation of the outer shell of the floating sleeve body. By a exzent ^¬ innovative arrangement of the inner diameter of the bearing sleeve body with respect to the outer diameter of the bearing bush body, the unbalance can be formed.

The abovementioned possibilities for producing a defined imbalance can, depending on requirements, be used both alternatively and in combination.

The imbalance introduced into the floating body counteracts an imbalance of the shaft during operation of the radial bearing.

Therefore high rotational speeds of the shaft occurring or developing instabilities in the Radi ^¬ allagers be avoided or at least greatly reduced in area. This leads advantageously to the fact that the probability of destruction of the radial bearing is reduced.

Hereinafter, embodiments of the invention with reference to Figures 3-8 are explained. FIG. 2 shows a perspective sketch of a conventional one

Swimming pool body, FIG. 3 is a sectional view of a floating bush body whose imbalance is formed by a stepped bore;

FIG. 4 shows a sectional view of a floating bush body whose unbalance is formed by a blind hole,

FIG. 5 shows a sectional view of a floating bush body whose imbalance is formed by a through-hole,

Figure 6 is a sectional view of a floating bush body, the imbalance is formed by an inner groove and Figure 7 is a perspective sketch of a Schwimmbüchsenkör ^¬ pers, the imbalance is formed by a deformation of the Au ^¬ ßenmantels the Schwimmbüchsenkörpers.

Figure 8 is a frontal view of a swimming pool body, whose

Imbalance is formed by the eccentric arrangement of the outer diameter of the ^¬ floating bucket to the inner diameter of the floating sleeve.

Function and naming equals objects or functional ^¬ units are consistently indicated in the figures with the same reference numerals.

In the figure 2 is a perspective sketch of a conventional swimming forth ^¬ can body 1 is shown. This buoy body 1 is substantially hollow cylinder-shaped or tubular with an outer diameter D _A and an inner diameter Di and has over its circumference evenly distributed more oil supply holes 2 through which in operation lubricating oil from the outside to the inside, ie from the outer lubrication gap to the inner Lubrication gap, is transported. These oil feed bores 2 generally run in the radial direction in each case, have a predetermined diameter and are designed as through bores. alisiert. The floating body 1 shown in Figure 2 is symmetrical and thus has no intentional imbalance. FIG. 3 shows a sectional view of a floating bush body 1 whose imbalance is formed by a stepped bore introduced into the floating bush body 1. This swimming pool body 1 is also substantially hollow cylindrical or tubular. It has a total of six oil supply bores 2, of which 5 are denoted by the reference numeral 2 and one by the reference numeral 3. This oil supply borehole 3 simultaneously serves to generate the imbalance of the floating bush body. It is designed to be stepped for this purpose, wherein it has in its radially outer region has a diameter which is greater than the diameter of the same bore in its radially inner region. Of the

Diameter of the bore 3 in its radially inner region coincides with the diameter of the holes 2 respectively. The diameter of the bore 3 in its radially outer region is greater than the diameter of the bore 3 in its radially inner region and thus larger than the diameter of the holes 2. This causes a targeted uneven mass distribution of the floating body over the circumference and thus in amount and location defined imbalance.

In the operation of the radial bearing, the imbalance of the floating bush body realized in the form of a stepped bore 3 counteracts an imbalance of the shaft in the entire rotational speed range of the shaft, in particular in the range of high rotational speeds, so that instabilities of the radial bearing and the probability of destruction of the bearing are reduced.

4 shows a sectional view of a floating bushing body, the unbalance is formed by at least one introduced into the outer circumference of the floating bush body blind hole bore ^¬. 4 This swimming pool body 1 is also substantially hollow cylindrical or tubular. He has a total of six evenly distributed over the circumference introduced oil supply holes 2. The blind hole 4 is used to generate the imbalance of the swimming pool body. The blind hole 4 may in principle have the same diameter as the oil supply holes 2, which allows the production in the same operation with the same tool. However, the blind bore 4 can also have a diameter different from the oil feed holes 2 if this is necessary for sufficient material removal to define the imbalance. This also causes a deliberately uneven mass distribution of the floating bush body over the circumference and thus an unbalance defined in magnitude and position.

The imbalance of the floating bush body implemented in the form of a blind bore 4 counteracts an imbalance of the shaft during operation of the radial bearing in the entire rotational speed range of the shaft, in particular in the area of high rotational speeds, so that instabilities of the radial bearing and the probability of destruction of the bearing are reduced. FIG. 5 shows a sectional view of a floating bush body whose imbalance is formed by a through bore introduced into the floating bush body. This swimming pool body 1 is also substantially hollow cylindrical or tubular. He has a total of six

evenly distributed over the circumference introduced oil supply holes, of which 5 are designated by the reference numeral 2 and one with the reference numeral 5a. This oil supply hole 5a simultaneously serves to generate the imbalance of the swimming ^¬ bushing body. It is designed for this purpose as a through hole whose diameter is constant and continuously larger than the diameter of the remaining holes 2. A corresponding result can alternatively be achieved by the arrangement of an additional through hole 5b (shown in phantom) between the equally distributed oil supply holes. 2 These two alternatives also cause a deliberately uneven mass distribution of the floating ^¬ bush body over the circumference and thus defined in magnitude and location unbalance. ₀

The imbalance of the floating bush body implemented in the form of a through-hole 5 counteracts an imbalance of the shaft during operation of the radial bearing in the entire rotational speed range of the shaft, in particular in the range of high rotational speeds, so that instabilities of the radial bearing and the probability of destruction of the bearing are reduced.

FIG. 6 shows a sectional view of a floating bush body whose imbalance is formed by an inner groove 6 introduced into the floating bush body. This swimming pool body 1 is also substantially hollow cylindrical or tubular. He has a total of six

evenly distributed over the circumference introduced oil supply holes, which are designated by the reference numeral 2 and the diameter of which match. Furthermore, the floating bush body on its inside a specifically di ^¬ dimensioned inner groove 6. This also causes a targeted uneven mass distribution of the floating body body over the circumference and thus defined in magnitude and location imbalance. Of course, the same result can be achieved by the arrangement of a corresponding outer groove on the outer circumference of the floating bush body 1 (not shown).

The unbalance of the floating bush body realized in the form of an internal groove 6 or external groove counteracts an imbalance of the shaft during operation of the radial bearing in the entire rotational speed range of the shaft, in particular in the range of high rotational speeds, so that instabilities of the radial bearing and the probability of destruction of the bearing are reduced ,

7 shows a perspective sketch of a floating ^¬ socket body, whose unbalance is formed by a deformation of the Au ^¬ ßenmantels of the floating bushing body. This swimming pool body 1 is also substantially hollow-cylindrical or tubular. He also has a total of six evenly distributed over the circumference ^¬ introduced oil supply holes 2 with matching diameters. The deformation of the outer shell of the swimming pool bush body can be realized for example by a material removal in the form of one or more chamfers or flats.

These alternatively or in addition to each other applicable features cause a targeted uneven mass distribution of the floating bush body over the circumference and thus defined in magnitude and location imbalance.

The imbalance of the floating bush body realized by a deformation of the outer jacket of the Schwimmbüch- body acts against the operation of the radial bearing in the entire Drehgeschwindig ^¬ keitsbereich the shaft, especially in the range of high rotational speeds, an imbalance of the shaft, so that instabilities of the radial bearing and the probability of destruction of the warehouse are reduced.

FIG. 8 shows a frontal view of a floating bush body whose imbalance is formed by the eccentric arrangement of the inner diameter of the floating bush body relative to the outer diameter of the floating bush body. For reasons of visibility, the relative position deviation E between the center _Ζ τ of the inside diameter and the center Z _A of the Au ^¬ ßendurchmessers is greatly oversubscribed. This measure also causes a deliberately uneven mass distribution of the floating bush body over the circumference and thus an unbalance defined in magnitude and location.

An imbalance equipped swimming pool body, as shown in Figures 3 to 8 and described above, is part of a radial bearing having a shaft mounted in a housing, the Schwimmbüchsenkörper is positioned between the housing and the shaft, wherein between the Shaft and the swimming pool body an inner lubrication gap and between the floating body and the housing is an outer lubrication gap.

During operation of such a radial bearing, in particular at high rotational speeds of the shaft, an imbalance of the shaft causes a force pulse on the lubricant film in the interior Lubricating gap. This force pulse is damped to some degree by the lubricant in the inner lubrication gap. The remaining residual pulse is on the located in the inner lubrication gap lubricant flow to the

Swimming pool body transmitted and basically causes a deflection of the swimming pool body relative to

Lubricating film in the outer lubrication gap. This deflection of the floating bush body counteract the inertia of the floating ^¬ bushing body itself and also damping forces of the lubricating film in the outer lubrication gap and cause a partial compensation of the deflection of the floating bush body. If the floating body - as explained above with reference to Figures 3 to 8 - equipped with an imbalance, then said counteracting is amplified, so that in particular in the range of high rotational speeds of the shaft, which are in the range of up to 120 m / s , the unwanted effects of shaft imbalances are largely compensated.

In order to determine the location or locations of the swimming pool body on which an unbalance must be provided in order to be able to counteract an imbalance of the shaft, examinations are carried out in the entire rotational speed range of the shaft in order to determine which positions on the swimming pool body with a defined Imbalance must be equipped to counteract an imbalance of the wave can.

Claims

claims

1. Radial bearing, which has a shaft rotatably mounted in a housing and provided between the housing and the shaft, rotatable in the housing about an axis of rotation Schwimmbüchsenkörper (1), wherein the Schwimmbüchsenkörper (1) in the manner of a hollow cylinder having an inner diameter (Di) , which receives the shaft and an outer diameter (D _A ) is formed for receiving in the housing and between the shaft and the inner diameter (Di) of the floating bush body (1) an inner lubrication gap and between the housing and the outer diameter (D _A ) of

Floating bush body (1) present an outer lubrication gap, characterized in that the floating bush body (1) is equipped with a defined imbalance (3,4,5,6,7) with respect to its axis of rotation.

2. Radial bearing according to claim 1, characterized in that the defined unbalance of the floating bush body (1), indicated as Ex ^¬ centricity, is in a range between 20% to 30% of a trained by the inner lubrication gap bearing clearance.

3. Radial bearing according to claim 1, characterized in that the defined imbalance of the buoyant body (1), as indicated eccentricity, in a range of 0.003 mm to 0.008 mm, in particular 0.005 mm.

4. Radial bearing according to one of claims 1 to 3, characterized in that the defined imbalance of the Schwimmbüch- senkörpers (1) of at least one in the Schwimmbüchsenkörper (1) introduced stepped bore (3) is formed.

5. Radial bearing according to one of claims 1 to 3, characterized in that the defined imbalance of the Schwimmbüch- senkörpers (1) of at least one in the Schwimmbüchsenkörper (1) introduced blind hole (4) is formed.

6. Radial bearing according to one of claims 1 to 3, characterized in that the defined imbalance of the Schwimmbüch ^¬ senkörpers (1) of a in the Schwimmbüchsenkörper (1) introduced through hole (5a, 5b) is formed.

7. Radial bearing according to claim 6, characterized in that the through hole (5 a) is an oil supply hole, whose diameter is larger than the diameter, in the Schwimmbüchsenkörper (1) provided further Ölzuführbohrungen (2).

8. Radial bearing according to claim 6, characterized in that the through-hole in addition to provided further oil supply holes (2) arranged through hole (5b).

9. Radial bearing according to one of claims 1 to 3, characterized in that the defined imbalance of the Schwimmbüch ^¬ senkörpers (1) of a in the Schwimmbüchsenkörper (1) introduced inner groove (6) is formed.

10. Radial bearing according to one of claims 1 to 3, characterized in that the defined imbalance of the Schwimmbüch ^¬ senkörpers (1) by a deformation (7) of the outer jacket of the Schwimmbüchsenkörpers (1) is formed.

11. Radial bearing according to claim 10, characterized in that the deformation (7) is formed by a removal of material on the outer jacket of the Schwimmbüchsenkörpers (1).

12. Radial bearing according to one of claims 1 to 3, characterized in that the defined imbalance of Schwimmbüch ^¬ senkörpers (1) by an eccentric arrangement of the inner ^¬ diameter (Di) of the floating bush body (1) with respect to the outer diameter (D _A ) the swimming pool body (1) is formed.