DE102018212517A1 - Tapered bearing with floating bush - Google Patents

Abstract

The invention relates to a sliding bearing (101, 103) with at least one conical outer sliding surface, at least one conical inner sliding surface and at least one floating bush (101b, 103b) arranged between the outer sliding surface and the inner sliding surface. A cone angle of the outer sliding surface is smaller or larger than a cone angle of the inner sliding surface.

Description

The invention relates to a plain bearing according to the preamble of claim 1.

The publication CN 107 299 966 A discloses a plain bearing with a tapered outer slide surface and a tapered inner slide surface. A planet gear is rotatably mounted on a planet pin in an O arrangement by means of two such bearings. Despite the O arrangement, the bearings cannot absorb axial forces because the bearing gaps collapse when axial forces act on the plain bearing. Thrust washers are therefore required to absorb axial forces.

Slide bearings with floating bushes are also known from the prior art. A floating bush is characterized in that it is arranged between an outer sliding surface and an inner sliding surface of the sliding bearing and is freely rotatable relative to the outer sliding surface and the inner sliding surface. The floating bush accordingly has a first and a second sliding surface. The first sliding surface forms a pair of sliding surfaces with the outer sliding surface, the second sliding surface forms with the inner sliding surface. A bearing gap runs between the sliding surfaces, which form a pair of sliding surfaces. This is either filled with lubricant or dry. The sliding surfaces of a pair of sliding surfaces can be rotated relative to one another about an axis of rotation of the sliding bearing.

The invention has for its object to improve the properties of tapered plain bearings compared to the solutions known from the prior art. In particular, a tapered plain bearing should be designed so that it can be loaded not only radially but also axially.

This object is achieved by a plain bearing according to claim 1. Preferred further developments are contained in the subclaims.

The plain bearing has at least one conical outer sliding surface and at least one conical inner sliding surface. A conical sliding surface has the basic shape of a lateral surface of a truncated cone. The basic shape of a surface denotes the shape of an original surface from which the first-mentioned surface is created by eliminating individual areas, for example by inserting recesses, and / or by adding individual areas. For example, the outer sliding surface and / or the inner sliding surface can have recesses for introducing, guiding or discharging lubricant.

The outer sliding surface is distinguished from the inner sliding surface in that it at least partially surrounds the inner sliding surface. The outer sliding surface forms the outer surface of a frustoconical cavity in which at least part of the inner sliding surface is located. Two planes running radially, that is to say orthogonally to an axis of rotation of the sliding bearing, can be specified, between which there are at least a part of the first sliding surface and at least a part of the second sliding surface.

The plain bearing has at least one floating bush. This is arranged between the outer sliding surface and the inner sliding surface. Accordingly, the first sliding surface of the floating bush forms a pair of sliding surfaces with the outer sliding surface. The second sliding surface of the floating bush forms a pair of sliding surfaces with the inner sliding surface. At least a part of the floating bush is located in the above-mentioned frustoconical cavity and between the two above-mentioned radial planes.

According to the invention, a cone angle of the outer sliding surface is smaller or larger than a cone angle of the inner sliding surface. The cone angle of a conical sliding surface denotes the cone angle of a corresponding truncated cone. This in turn is the opening angle of a cone, which consists of the truncated cone and a supplementary cone. The opening angle denotes the angle that two surface lines, which are arranged with a central axis of the cone in a common plane, form. The opening angle is twice an angle between a surface line and the central axis.

The different cone angles of the outer and inner sliding surfaces have the result that a radial force acting on the slide bearing causes a force acting on the floating bush in the axial direction. This ensures that at least one bearing gap of the plain bearing is retained with an axial force acting on the plain bearing. As a result, the plain bearing remains rotatable even under axial load.

In a preferred development, the first sliding surface and the second sliding surface of the floating bush are each conical. A cone angle of the first sliding surface is smaller or larger than a cone angle of the second sliding surface. If the cone angle of the outer sliding surface is smaller than the cone angle of the inner sliding surface, the cone angle of the first sliding surface of the floating bush is preferably smaller than the cone angle of the second sliding surface of the floating bush. If the cone angle of the outer sliding surface is greater than the cone angle of the inner sliding surface, the conical angle of the first sliding surface of the floating bush is preferred larger than the cone angle of the second sliding surface of the floating bush.

In a preferred development, the cone angle of the outer sliding surface and the cone angle of the first sliding surface of the floating bush match. According to a further development, the taper angle of the inner sliding surface and the taper angle of the second sliding surface of the floating bush also match.

The plain bearing is preferably developed as a first plain bearing of an arrangement which also has a second plain bearing of the type described above. The first slide bearing and the second slide bearing are arranged in an O arrangement. This means that the sliding surfaces of the first plain bearing taper in the direction of the second plain bearing. The sliding surfaces of the second slide bearing also taper in the direction of the first slide bearing. The diameters of the sliding surfaces of the two plain bearings are therefore central, i.e. between the plain bearings, the smallest and become axially larger towards the outside.

According to a further development, the taper angle of the outer sliding surface of the first sliding bearing is smaller than the taper angle of the inner sliding surface of the first sliding bearing; the cone angle of the outer slide surface of the second slide bearing is smaller than the cone angle of the inner slide surface of the second slide bearing. The effect described at the outset then causes a radial load on the first plain bearing and the second plain bearing to be accompanied by forces which act on the floating bush of the first plain bearing and the floating bush of the second plain bearing and are directed axially inward.

The two floating bushes are preferably arranged so that they are supported against each other. This prevents the floating bush from shifting inwards. As a result, all bearing gaps of the first slide bearing and the second slide bearing are retained.

Alternatively, the first slide bearing and the second slide bearing can be developed in an X arrangement. The cone angle of the outer sliding surface of the first sliding bearing is larger than the cone angle of the inner sliding surface of the first sliding bearing. Accordingly, the cone angle of the outer sliding surface of the second sliding bearing is larger than the cone angle of the inner sliding surface of the second sliding bearing. Here, too, inward axial forces act on the two floating bushes when the first plain bearing and the second plain bearing are subjected to radial loading.

The first slide bearing and the second slide bearing are preferably mirror-symmetrical to a plane running radially, that is to say orthogonally to a common axis of rotation of the first slide bearing and the second slide bearing.

The arrangement is preferably further developed with a planet gear and a planet pin. The planetary gear is rotatably mounted on the planet pin by means of the first plain bearing and the second plain bearing. Such an arrangement is particularly advantageous if the planet gear is helically toothed and the bearings have to absorb axial forces from the toothing.

In a preferred development, the planet gear is made in one piece and forms the outer sliding surface of the first sliding bearing and the outer sliding surface of the second sliding bearing. If the sliding surfaces are integrated in the planet gear, the assembly of the arrangement is particularly simple.

• 1 eine Gleitlageranordnung.

A preferred embodiment of the invention is in 1 shown. In detail shows:

• 1 a plain bearing arrangement.

The plain bearing arrangement comprises a first plain bearing 101 and a second plain bearing 103 , The plain bearings 101 . 103 are on a planet bolt 105 arranged and serve the rotatable mounting of a 1 not shown planet gear.

The two plain bearings 101 . 103 each have an inner ring 101 . 103a , a floating bush 101b . 103b and an outer ring 101c . 103c on. The inner rings 101 . 103a form inner sliding surfaces, the outer rings 101c . 103c correspondingly outer sliding surfaces. Between the inner ring 101 and the floating bush 101b and between the outer ring 101c and the floating bush of the first plain bearing 101 as well as between the inner ring 103a and the floating bush 103b and between the outer ring 103c and the floating bush 103b of the second plain bearing 103 there is a bearing gap in each case.

The first plain bearing 101 tapers towards the second plain bearing 103 , The second plain bearing tapers accordingly in the direction of the first plain bearing. This means that the diameter of the inner rings 101 . 103a the floating bushes 101b . 103b and the outer rings 101c . 103c of the first plain bearing 101 and the second plain bearing 103 decrease in the direction of the other plain bearing. The inner, ie between the inner rings 101 . 103a and the floating bushes 101b . 103b running bearing gaps taper more than the outer, i.e. between the outer rings 101c . 103b and the floating bushes 101b . 103b trending bearing columns.

As a result, radial forces introduced via the planet gear act in the floating bushes 101b . 103b than inwards, ie to the other plain bearing 101 . 103 directed axial forces. This prevents the inner bearing gaps from collapsing when axial forces occur. Because the floating bushes 101b . 103b supported against each other, it also prevents the outer bearing columns from collapsing.

LIST OF REFERENCE NUMBERS

101

first plain bearing

103

second plain bearing

105

planet shaft

101

Inner ring of the first plain bearing

103a

Inner ring of the second plain bearing

101b

Floating bush of the first plain bearing

103b

Floating bushing of the second plain bearing

101c

Outer ring of the first plain bearing

103c

Outer ring of the second plain bearing

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• CN 107299966 A [0002]

Claims (7)

Plain bearings (101, 103) with at least one conical outer sliding surface, at least one conical inner sliding surface and at least one floating bush (101b, 103b) arranged between the outer sliding surface and the inner sliding surface; characterized in that a cone angle of the outer sliding surface is smaller or larger than a cone angle of the inner sliding surface. Plain bearings (101, 103) after Claim 1 ; characterized in that the floating bush (101b, 103b) has a conical first sliding surface which forms a pair of sliding surfaces with the outer sliding surface; wherein the floating bush (101b, 103b) has a tapered second sliding surface which forms a pair of sliding surfaces with the inner sliding surface; wherein a cone angle of the first sliding surface of the floating bush (101b, 103b) is smaller or larger than a cone angle of the second sliding surface of the floating bush (101b, 103b). Slide bearing (101, 103) according to the preceding claim; characterized in that the taper angle of the outer sliding surface and the taper angle of the first sliding surface of the floating bush (101b, 103b) match; wherein the cone angle of the inner sliding surface and the cone angle of the second sliding surface of the floating bush (101b, 103b) match. Arrangement with a first slide bearing (101) according to one of the preceding claims; characterized by a second slide bearing (103) according to one of the preceding claims; the first and second slide bearings (101, 103) being arranged in an O arrangement; wherein the cone angle of the outer sliding surface of the first sliding bearing (101) is smaller than the cone angle of the inner sliding surface of the first sliding bearing (101); and wherein the taper angle of the outer sliding surface of the second sliding bearing (103) is smaller than the taper angle of the inner sliding surface of the second sliding bearing (103). Arrangement with a first slide bearing (101) according to one of the Claims 1 - 3 ; characterized by a second slide bearing (103) according to one of the Claims 1 - 3 ; the first and second slide bearings (101, 103) being arranged in an X arrangement; wherein the cone angle of the outer sliding surface of the first sliding bearing (101) is greater than the cone angle of the inner sliding surface of the first sliding bearing (101); and wherein the taper angle of the outer sliding surface of the second sliding bearing (103) is greater than the taper angle of the inner sliding surface of the second sliding bearing (103). Arrangement according to one of the preceding two claims; characterized by a planet gear and a planet pin (105); wherein the planet gear is rotatably mounted on the planet pin (105) by means of the first and the second slide bearing (101, 103). Arrangement according to the preceding claim; characterized in that the planet gear is made in one piece and forms the outer sliding surface of the first sliding bearing (101) and the outer sliding surface of the second sliding bearing (103).

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