Non-circular sliding surface

Abstract

The present invention relates to an inner sliding surface (101) for a centripetal sliding bearing, the inner sliding surface comprising at least one cross-section formed by four arcs (111, 113, 115, 117); wherein, a first arc (111) and a second arc (113) are located on different sides of a longitudinal section plane that intersects a third arc (115), a fourth arc (117), and a common center point (125) of the third arc (115) and the fourth arc (117). The first arc (111) and a center point (121) of the first arc (111) are located on different sides of the longitudinal section plane (119); wherein, the second arc (113) and a center point (123) of the second arc (113) are located on different sides of the longitudinal section plane (119).

Description

Technical field

[0001] The present invention relates to a sliding surface and a method. The task is to improve the durability and load capacity of a sliding bearing. Summary of the invention

[0002] The sliding surface according to the invention is the inner sliding surface of a radial sliding bearing. A radial sliding bearing is a sliding bearing which, in addition to having an inner sliding surface, also has an outer sliding surface. The two sliding surfaces are arranged in such a way that they can transmit forces in the radial direction, i.e. forces orthogonal to the axis of rotation of the radial sliding bearing. The transmission of the forces takes place respectively between the inner sliding surface and the outer sliding surface.

[0003] In a pure radial sliding bearing, it is not possible to transmit forces in the axial direction. If it is a combined radial thrust sliding bearing, it is also possible to transmit forces in the axial direction, i.e. in the direction of the axis of rotation.

[0004] The inner sliding surface and the outer sliding surface can be twisted relative to each other about the axis of rotation mentioned above. They form a sliding surface pair. The sliding surface pair is characterized in that its sliding surfaces form a bearing clearance. This bearing clearance is dry or at least partially filled with a lubricant.

[0005] The outer sliding surface surrounds the inner sliding surface. At least one, preferably each, perpendicular from the outer sliding surface to the axis of rotation intersects the inner sliding surface. In addition, any distance of any point of the outer sliding surface from the axis of rotation is greater than any distance of any point of the inner sliding surface from the axis of rotation.

[0006] In at least one cross-section, the outer sliding surface forms a self-closed curve which encloses an area. A part of this area is formed by the self-closed curve formed by the inner sliding surface in this cross-section.

[0007] The at least one cross-section is characterized by a radial orientation. Accordingly, the corresponding cutting plane extends orthogonally to the axis of rotation of the radial sliding bearing.

[0008] In at least one cross-section, preferably in each cross-section, the inner sliding surface or the curve formed by the inner sliding surface is formed by four circular arcs. Accordingly, the inner sliding surface consists of a first circular arc, a second circular arc, a third circular arc and a fourth circular arc. These circular arcs are adjacent to each other. Specifically, the first circular arc is adjacent to the third circular arc and the fourth circular arc. The third circular arc is adjacent to the first circular arc and the second circular arc, the second circular arc is adjacent to the third circular arc and the fourth circular arc. Finally, the fourth circular arc is adjacent to the first circular arc and the second circular arc. Accordingly, the first circular arc and the third circular arc have a common vertex. Similarly, the third circular arc and the second circular arc, the second circular arc and the fourth circular arc, and the fourth circular arc respectively have a common vertex.

[0009] The first arc and the second arc are completely located on different sides of the longitudinal section plane. The longitudinal section plane is characterized by having an axial orientation. Accordingly, this longitudinal section plane is parallel to the rotational axis of the centripetal sliding bearing. Preferably, the longitudinal section plane extends through the rotational axis, such that the rotational axis is completely contained within the longitudinal section plane.

[0010] The longitudinal section plane intersects the third arc and the fourth arc, as well as the point forming the center points of the third arc and the fourth arc.

[0011] The center point of an arc refers to the center point of the respective circle, i.e., the circle of which the arc forms a segment. The vertices of the arc are here those points of the circle that are connected to each other by the arc and bound the arc outwardly. The vertices are characterized in that the other points of the arc are not on both sides of their respective vertex, but only on one side of their respective vertex.

[0012] According to the invention, the first arc and its center point are completely located on different sides of the longitudinal section plane. Similarly, the second arc and its center point are completely located on different sides of the longitudinal section plane. This means that the center points of the first arc and the second arc are located on the same side of the longitudinal section plane, and similarly, the center points of the second arc and the first arc are also located on the same side of the longitudinal section plane.

[0013] The non-circular shape of the inner sliding surface is obtained by the inventive design of the arc. This improves the load capacity and durability of the centripetal sliding bearing.

[0014] In a preferred refinement, the center point of the first arc and the center point of the second arc are mirror-symmetrical to each other. The mirror plane is here formed by the aforementioned longitudinal section plane. Furthermore preferably, the entire cross-section of the inner sliding surface, i.e., the curve of the inner sliding surface located in the transverse plane, is also mirror-symmetrical with respect to the same longitudinal section plane. Furthermore preferably, the three center points (i.e., the center point of the first arc, the center point of the second arc, and the common center point of the third and fourth arcs) are arranged on a straight line that intersects all three center points.

[0015] In another preferred refinement, the radius of the first arc or the respective circle is greater than the radius of the third arc or the respective circle and greater than the radius of the fourth arc or the respective circle. Furthermore preferably, the radius of the second arc or the respective circle is greater than the radius of the third arc and greater than the radius of the fourth arc. The radius of the third arc and the radius of the second arc are here preferably the same. Similarly, the radius of the third arc is preferably equal to the radius of the fourth arc.

[0016] The sliding surface is preferably refined to be the inner sliding surface of a centripetal sliding bearing. The centripetal sliding bearing has an outer sliding surface that forms a sliding pair with the inner sliding surface.

[0017] The centripetal sliding bearing is preferably improved to be part of a planetary stage. The planetary stage includes a ring gear, a sun gear, a planet carrier, and at least one planet gear. The planet gear is rotatably supported on a planet pin fixed to the planet carrier. At least one planet gear meshes with the sun gear and / or the ring gear. Currently, the planet gear is supported on the planet pin by means of a centripetal sliding bearing. This is particularly advantageous because the load area in the bearing of the planet gear is static relative to the planet carrier. Also, the position of the inner sliding surface of the centripetal sliding bearing is static relative to the planet carrier. Therefore, the shape of the inner sliding surface is also static relative to the load area. By an appropriate orientation of the inner sliding surface relative to the load area, an improved load capacity can be achieved.

[0018] In a preferred improvement, the planet pin integrally forms the inner sliding surface of the centripetal sliding bearing. Alternatively, the planet pin can have a bushing that integrally forms the inner sliding surface. In this case, the planet pin consists of the bushing and a base body on which the bushing is fixed. The bushing and the base body are physically separate components. The outer sliding surface of the centripetal sliding bearing is preferably integrally formed by a floating bushing or a planet gear respectively.

[0019] The inner sliding surface according to the invention can be manufactured by means of a lathe. Here, a three-step method is used, in which the workpiece is re-clamped twice. The workpiece rotates about three different axes here. The corresponding method according to the invention includes the following steps:

[0020] - Turning the workpiece, wherein the workpiece rotates about an axis extending through the center point of a first circular arc. Here, a section of the inner sliding surface containing the first circular arc is made.

[0021] - Turning the workpiece, wherein the workpiece rotates about an axis extending through the center point of a second circular arc. In this step, a section of the sliding surface containing the second circular arc is made.

[0022] - Turning the workpiece, wherein the workpiece rotates about an axis extending through the common center point of a third circular arc and a fourth circular arc. Thereby, two sections of the inner sliding surface are made, one section containing the third circular arc and one section containing the fourth circular arc.

[0023] The step of turning the workpiece about an axis extending through the common center point of the third circular arc and the fourth circular arc is preferably carried out after the step of turning the workpiece about an axis extending through the center point of the first circular arc and the step of turning the workpiece about an axis extending through the center point of the second circular arc. Description of the Drawings

[0024] A preferred embodiment of the invention is shown in Figure 1 in which in detail:

[0025] Figure 1Show the inner sliding surface;

[0026] Figure 1 Cross-sectional view showing the inner sliding surface. Detailed implementation

[0027] Figure 1 The sliding surface 101 shown in the figure has vertices of four arcs, namely the first vertex 103, the second vertex 105, the third vertex 107, and the fourth vertex 109. In the cross-sectional view, the sliding surface 101 is composed of the first arc 111, the second arc 113, the third arc 115, and the fourth arc 117. The first vertex 103 and the fourth vertex 109 are the vertices of the first arc 111. The vertices of the second arc 113 exist in the form of the second vertex 105 and the third vertex 107. The first vertex 103 and the second vertex 105 are the vertices of the third arc 115. The third vertex 107 and the fourth vertex 109 are the vertices of the fourth arc 117. Therefore, the first arc 111 and the third arc 115 meet at the first vertex 103. The third arc 115 and the second arc 113 meet at the second vertex 105. The second arc 113 and the fourth arc 117 meet at the third vertex 107. The fourth arc 117 and the first arc 111 meet at the fourth vertex 109.

[0028] The sliding surface 101 is mirror-symmetrical with respect to the longitudinal cross-sectional plane 119. The longitudinal cross-sectional plane 119 extends orthogonally to the transverse plane equivalent to Figure 1 the drawing surface.

[0029] The center point 121 of the first arc 111 and the first arc 111 are on different sides of the longitudinal cross-sectional plane 119. In addition, the center point 123 of the second arc 113 and the second arc 113 are on different sides of the longitudinal cross-sectional plane 119. The common center point 125 of the third arc 115 and the fourth arc 117 is between the two center points 121 and 123. The common center point 125 intersects the longitudinal cross-sectional plane 119. All three center points 121, 123, and 125 are also on a straight line, which extends in the above-mentioned transverse plane and is oriented orthogonally to the longitudinal cross-sectional plane 119. In addition, the rotation axis of the centripetal sliding bearing extends through the common center point 125, and the inner sliding surface of this centripetal sliding bearing forms the sliding surface 101.

[0030] List of reference numerals

[0031] 101 Sliding surface

[0032] 103 First vertex

[0033] 105 Second vertex

[0034] 107 Third vertex

[0035] 109 Fourth vertex

[0036] 111 First circular arc

[0037] 113 Second circular arc

[0038] 115 Third circular arc

[0039] 117 Fourth circular arc

[0040] 119 Longitudinal section plane

[0041] 121 Center point of the first circular arc

[0042] 123 Center point of the second circular arc

[0043] 125 Center points of the third and fourth circular arcs

Claims

1. Inner sliding surface (101) for a centripetal sliding bearing, the inner sliding surface being formed by four arcs (111, 113, 115, 117) in at least one cross-section; wherein, The first arc (111) and the second arc (113) are located on different sides of a longitudinal section plane that intersects the third arc (115), the fourth arc (117), and the common center point (125) of the third arc (115) and the fourth arc (117); characterized in that, The first arc (111) and the center point (121) of the first arc (111) are located on different sides of the longitudinal section plane (119); wherein The second arc (113) and the center point (123) of the second arc (113) are located on different sides of the longitudinal section plane (119).

2. The inner sliding surface (101) according to claim 1; characterized in that, The center point (121) of the first arc (111) and the center point (123) of the second arc (113) are mirror-symmetrical to each other with respect to the longitudinal section plane (119).

3. The inner sliding surface (101) according to claim 1 or 2; characterized in that, The radius of the first arc (111) is greater than the radius of the third arc (115) and greater than the radius of the fourth arc (117).

4. Centripetal sliding bearing; characterized in that Having The inner sliding surface (101) according to any one of claims 1 to 3 and a cylindrical outer sliding surface; wherein The inner sliding surface (101) and the outer sliding surface form a sliding pair.

5. A planetary stage having at least one planet gear and at least one planet pin; characterized in that Having At least one centripetal sliding bearing according to claim 4; wherein, The planet gear is supported on the planet pin by means of the centripetal sliding bearing.

6. The planetary stage according to claim 5; characterized in that, The planet pin integrally forms the inner sliding surface (101) of the centripetal sliding bearing.

7. A method for manufacturing a component having an inner sliding surface (101) according to any one of claims 1 to 3; the method having the following steps: - Turning the workpiece, wherein, Rotating the workpiece about an axis extending through the center point (121) of the first arc (111); - Turning the workpiece, wherein the workpiece is rotated about an axis extending through the center point (123) of the second arc (113); - Turning the workpiece, wherein the workpiece is rotated about an axis extending through the center point (125) of the third arc (115) and the fourth arc (117).

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