WO2023093940A1

WO2023093940A1 - Thrust washer, and planetary gearbox having at least one thrust washer of this type

Info

Publication number: WO2023093940A1
Application number: PCT/DE2022/100869
Authority: WO
Inventors: Wolfgang Fugel; Andreas CHRISTL
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2021-11-26
Filing date: 2022-11-21
Publication date: 2023-06-01

Abstract

The invention relates to a thrust washer (1) and to a planetary gearbox. The thrust washer is to be disposed between a planet gear (18) and a planet carrier (21) of a planetary gearbox (12). On the washer side (2) facing the planet gear (18), one or more radially extending oil-guiding grooves (6) are provided, which are radially open at the outer contour (7) and at the inner periphery (8) of the washer (1). The or each oil-guiding groove (6) is wider at the outer end than at the inner end. The or each oil-guiding groove (6) leads to a radial recess (9) provided at the inner periphery (8).

Description

Thrust washer and planetary gears with at least one such thrust washer

The invention relates to a thrust washer with a central axial through hole and with two sides of the disk facing away from one another, at least one of the sides of the disk being provided with at least one oil guide groove extending radially, the oil guide groove being formed on the circumferential side between contact surfaces pointing in the axial direction on the at least one side of the disk and wherein the oil guide groove is open towards the outer contour of the thrust washer and towards the through hole, and wherein the oil guide groove is wider at its end ending on the outer contour than the inner end ending at the through hole, with the oil guide groove ending in a radial recess provided on the inner circumference.

Ring-shaped thrust washers of this type are used for the axial start-up of the planet gear and protect the planet carrier and the planet gears from wear. The planet gear runs with a flat front surface against the flat contact surface of the thrust washer. The planetary gear is rotatably mounted on a planetary pin fixed to the planetary carrier via a roller bearing, usually a needle bearing.

Examples of such thrust washers, such as those according to JP 2017 - 180 584 A and DE 10 2019 212 217 A1, are designed in the manner of hydrodynamic bearings, i.e. their oil guide grooves have a wedge-shaped cross section, which is predetermined by ramp-like formations of the groove base of the oil guide grooves. Oil guide grooves are wider at the outer end than at the inner end. A passage of oil through the respective thrust washer is ensured in that each oil guide groove opens into a radial recess provided on the inner circumference.

To supply the roller bearing as well as to lubricate the surfaces running axially against one another, the planetary bolt is usually provided with an axially extending blind bore provided, from which at least one radial bore goes off, which opens out on the bolt lateral surface, ie immediately below the needle bearing. The oil is guided from the inside into the bearing area via this bore structure, usually in conjunction with an oil-collecting oil drip tray, from where it is distributed in the bearing area itself on the one hand, but also reaches the wheel and disk surfaces that abut one another on the other. In order to improve the distribution of the oil in the area of the wheel and disk surfaces that run against one another, it is known to provide the thrust disk, which is regularly fixed in position on the planet carrier, with several lubricant grooves on the disk side facing the planetary gear face, as shown for example in US Pat. No. 3,597,027 A. These lubricant grooves open out on the inner circumference and on the outer circumference of the ring-shaped thrust washer, with the respective lubricant groove being wider at the inner circumferential end than at the outer circumferential end, ie it narrows outwards in the radial direction. The oil flowing in from the inside is caught on the inner circumference via the wide opening cross section of the lubricant groove and can be distributed in the lubricant groove due to rotation and discharged to the outside. The surfaces that come into contact with one another are lubricated by the oil in the lubricant grooves, so that despite the rotational movement of the front face of the planet wheel, there is no appreciable wear when it comes into contact with the fixed disk surface.

In known planetary carriers, as described above, the oil is supplied from the inside, ie via the correspondingly hollow planetary pin. The formation of the bore structure is correspondingly complex, as is the production and assembly of an oil drip tray as a separate component.

The invention is based on the object of specifying a thrust washer that enables a simplified configuration of a planetary gear.

To solve this problem, a thrust washer according to the features of claim 1 and a planetary gear with such a thrust washer according to claim 8 are provided. It is provided that a. each oil guiding groove has two groove sections which are identical to one another and are mirror images of an imaginary line of symmetry, b. the thrust washer has an overall thickness which is greater than the starting thickness of a metal sheet, the overall thickness being an axial dimension between the axially most protruding contours of the sides of the washer and the thrust washer being formed from the metal sheet, c. the axial depth of the oil guide groove is described over its entire course from the through-hole to the outer contour and between two opposite walls by an axial depth dimension that remains constant over the course, with the axial depth dimension being a difference between the total thickness of the thrust washer and a radial course of the The through hole is of constant sheet metal thickness towards the outer contour, and the sheet metal thickness is a distance which exists axially between the groove base of the oil guide groove (6) and the side of the disk facing away from the oil guide groove.

Embodiments of the invention provide

- that the sheet thickness corresponds to the initial thickness of the metal sheet. that the walls are mirror images of each other and are designed to be geometrically identical.

that at least three oil guide grooves and radial recesses are provided, distributed equidistantly around the circumference. that if there are several oil guide grooves, all the oil guide grooves have the same geometry and the same course, or that oil guide grooves of different geometries with different widths are provided, that an anti-rotation element is provided, which protrudes from one side of the disk and is located radially opposite the end of an oil guide groove.

The thrust washer according to the invention makes it possible to guide the oil from radially outside into the thrust area as well as the bearing area. This means that, if necessary, an oil supply from the inside via the planet bolts in connection with a Lubricant drip tray can be dispensed with or that the oil supply to the planetary bearings is improved. For this purpose, the thrust washer according to the invention has at least one oil guiding groove, which has a specific groove geometry. A plurality of such oil guide grooves are preferably provided. One or the respective oil guide groove, which is radially open on the outer and inner circumference, ie on the edge of the central through-hole, is wider on the outer contour than on the inner circumference, ie it narrows from radially outside to radially inside. On the inner circumference, the or each lubricant groove opens into a radial recess, that is to say a recess which locally widens the inner diameter of the disk. The planet bolt penetrates the central mounting hole of the thrust washer with little play. The needle bearing follows the planetary pin radially. Due to the design of the radial recesses, the oil flowing in via the oil guide groove from radially outside reaches the bearing area more quickly, while during the flow through the lubricant groove it naturally also reaches the area of the surfaces of the planet wheel and the thrust washer that abut and rotate relative to one another.

This specific geometry of the oil guide groove makes it possible to convey the scooped or dripping oil or the oil foam from radially outside to radially inside and to feed it to the bearing area. The front face of the planetary gear is arranged at a minimum distance from the oil guide groove or, in the event of a start, rests against the thrust washer. The oil guide groove therefore forms a kind of funnel towards the outside. This means that the oil can enter from radially outside or initially reaches the entrance of the oil guide groove via the surrounding structure, and this can also take place when passing through an oil sump in the planetary gear.

The thrust washer according to the invention thus makes it possible to design the planetary gear or the planetary wheel bearing in a simpler way, since simple, solid and non-drilled planetary bolts can be used, and an oil drip tray can also be dispensed with.

Preferably, at least three, preferably four oil guide grooves and radial recesses distributed equidistantly around the circumference are provided, so that a correspondingly large groove or nozzle volume, through which the oil can be conveyed inwards and can escape at various positions around the circumference.

It is conceivable that with several oil guide grooves, all oil guide grooves have the same geometry, in particular the same width profile. Alternatively, it is also conceivable that oil guide grooves with different geometries, in particular with different widths, are provided. This means that the disk side can either be segmented symmetrically if all oil guiding grooves have the same geometry or the same width. However, a varying segmentation is also conceivable, in which case the inflow of the oil into the bearing area can be varied locally via the corresponding groove geometry or groove width. As described, the thrust washer is fixed in position on the planet carrier, while the planet gear rotates relative to it. This means that the lubricant grooves are also fixed in position. If there is a specific preferred direction from which the oil flows, e.g. from radially inward via a corresponding oil outlet of the sun gear of the planetary gear, one or more of the oil guide grooves that are adjacent to this feed area can be wider than the lubricant grooves that are distant from it.

Preferably the or each oil guide groove is drawn or coined or otherwise cold formed. This means that the thrust washer consists of a corresponding sheet metal or metal strip and is correspondingly formed by deep-drawing to form the oil groove structure. The material thickness does not change as a result of this drawing process, and consequently neither do the corresponding properties of the thrust washer resulting from the material thickness.

Particularly preferably, the disk sides on both sides of the thrust washer according to the invention are planar, but are provided with a height relief due to drawing. As a result, relief-like structures in the form of elevations and depressions form on both sides of the disk, the sides of the disk being planar despite the resulting structures or reliefs, so that there is a planar contact surface in particular on the side facing the planet wheel forms and the planetary gear end face has a correspondingly large surface contact with the thrust washer in the event of a start.

Another advantage of deep-drawing without changing the material thickness and in particular the design with the two parallel flat disk surfaces is that the total thickness of the thrust washer can be easily varied and adjusted in relation to the given installation space. This allows you to work with extremely small tolerances. It is also advantageous that a correspondingly thin metal sheet can be used as the starting material, with the final total thickness of the thrust washer being greater than the starting thickness of the metal sheet. For example, a metal sheet or metal strip with a thickness of 0.65 mm is used, which is correspondingly deep-drawn to form the lubricant grooves and, for example, has a final total thickness of 1 mm when forming a groove depth of 0.35 mm described by the axial depth dimension. The numerical values given are only examples, of course a slightly thinner or thicker metal strip can also be used in the application, just as the axial depth dimension can of course also be selected differently and thus also the resulting pane thickness.

Furthermore, a connecting element can be provided which protrudes on the disk side facing the planet carrier. A torsion-proof positioning of the thrust washer relative to the planet carrier is ensured via this anti-twist element. The axially protruding anti-rotation element engages in a corresponding receptacle on the planet carrier, so that this engagement prevents the thrust washer from rotating.

According to the invention, it is also provided that the anti-rotation element interacting with the planet carrier of the planetary gear is formed at the outer open end, i.e. radially outside at the outlet or inlet of the oil guide groove in the bottom of the groove, i.e. in the recessed area, of at least one of the oil guide grooves. Such an arrangement allows the thrust washer to be produced optimally. The geometry of the anti-rotation element essentially includes the initial strength of the sheet metal for the production of the thrust washer, can be integrated into the cutting of the sheet metal blank and remains essentially unaffected by the deformations in the forming process of the washer.

Furthermore, an anti-wear coating can be applied at least to the disk side facing the planet wheel. Of course, the thrust washer can also be coated on all sides with such a wear protection coating, which is possible in particular if the wear protection coating is applied as part of a drum coating.

In addition to the thrust washer itself, the invention also relates to a planetary gear comprising a planetary carrier and several planetary gears rotatably mounted thereon on respective planetary bolts, each planetary gear being offset axially towards the planetary carrier via at least one thrust washer of the type described above. Each planet wheel is preferably supported on both axial sides via two such thrust washers, with the two thrust washers being of identical design.

Usually, such a planetary gear has a sun wheel, which meshes with its teeth with the toothed planet wheels and consequently rotates relative to the planet carrier. Oil is preferably supplied via a central shaft which passes through the sun gear and has a corresponding channel structure, which oil emerges radially from the shaft via a radial bore in the channel structure and reaches the sun gear on the inside. The sun gear has one or more radial bores, with the oil exiting radially via the one or more radial bores and optionally via an axial bearing, via which the sun gear is mounted axially on the shaft, and from radially inside to the planet gears and their arrangement on the planet bolts reached. Due to the supply and rotation, the oil escapes under pressure in the direction of the planet gears and can thus easily enter the open oil guide grooves on the inner circumference of the planet gears arranged on a circular path, from where it is then sucked further radially inwards into the bearing area. The invention is explained below using exemplary embodiments with reference to the drawings. The drawings are schematic representations and show:

Figure 1 is a perspective view of a thrust washer according to the invention,

Figure 2 is a plan view of the thrust washer from Figure 1, and

FIG. 3 shows a sectional representation of the principle of a planetary gear with thrust washers serving to support the planetary gears.

FIGS. 1 and 2 show a thrust washer 1 according to the invention, which was produced from a thin metal strip formed by deep-drawing and having a total thickness of between, for example, 0.6 to 1.0 mm. The thrust washer 1 has an even or planar first disk side 2, which is described in Figure 3 and which, in the assembly position, is positioned axially directly adjacent to the end face of a planet gear to be supported on the thrust washer 1, the planet gear with its end face against the disk side 2 running. On the other side there is an opposite, likewise flat or planar second disk side 3 which, in the assembled position, bears flat against a support surface of a planetary carrier. For torsion-proof anchoring, an anti-rotation element 4 is provided on the thrust washer 1 in the form of an anti-rotation element 4 that first extends radially and then at an angle in the axial direction, which engages in a corresponding receptacle on the planetary carrier, so that the thrust washer 1 is coupled to the planetary carrier in the assembly position relative to the planetary carrier is.

The thrust washer 1 is otherwise ring-shaped and has a central receiving bore 5 through which a planet bolt, on which a planet wheel is rotatably mounted via a bearing device, engages in the assembled position.

The thrust washer 1 made of the thin metal strip is shaped accordingly, as described, with this shaping on the one hand Anti-rotation element 4 is formed, but on the other hand, corresponding profiles are also formed on both sides of the pane 2, 3, with the pane thickness not changing as a result of the deep-drawing despite the forming. As a result of the reshaping, four oil guide grooves 6 are formed on the disk side 2 pointing towards the planet wheel in the assembly position in the example shown, which extend radially and are open towards the outer contour 7 at the outer end, just as they are open towards the inner circumference 8 at the inner end. The oil guide grooves 6 have a V-shaped geometry, see also FIG. They are significantly wider at the outer end directed toward the outer contour 7 than at the end open toward the inner circumference 8, that is, they narrow from radially outward to radially inward. On the inner circumference 8, the oil guide grooves 6 open into corresponding radial recesses 9, via which the inner circumference is locally enlarged radially. These radial recesses 9 ensure that the oil flowing through the oil guide grooves 6 from radially outside to radially inside can escape early towards the bearing unit.

The areas to the left and right of the respective oil guide groove 6 are of course raised with respect to the respective oil guide groove 6 and are designed to be closed radially on the inner circumference, i.e. they rise up relative to the bottom surface of the oil guide grooves 6 and close radially on the inside to the level of the inner circumference. In the assembly position, when consequently the thrust washer 1 is mounted on the planet bolt, the thrust washer 1 lies flat against the planet carrier with the disk side 3, which is formed by the flat rear sides of the oil guide grooves 6. Equally, however, the thrust washer 1 also rests in the area of the inner circumference all the way around between the oil guide groove rear sides on the planet carrier. As a result, via the raised sections 10 between the oil guide grooves 6, corresponding pockets 11, which are virtually closed downwards, are formed between the thrust washer 1 on the one hand and the planetary carrier on the other hand, in which pockets oil can also collect. After the thrust washer 1 is not in fluid-tight contact with the planet carrier on the one hand and is not seated fluid-tight on the planet bolt on the other hand, this oil can flow off more or less inwardly towards the planet bolt, although due to the narrow given distances or clearances only in to a lesser extent. In any case, a supply of lubricant from radially outside into the bearing area is also possible via these pockets 11, which form a quasi oil reservoir.

FIG. 3 shows a sectional representation of the principle of a planetary gear 12 according to the invention, comprising a central shaft 13 on which a sun wheel 14 is axially rotatably mounted via an axial bearing 15 . The toothing 17 of the respective planet wheel 18 meshes with a toothing 16 of the sun wheel. A plurality of planet gears 18 together with planet bolts 20 are arranged on the planet carrier 21 on a circular path. A thrust washer 1 according to the invention is arranged on both sides between the planet wheel 18 and the planet carrier 21, which is secured against rotation on the planet carrier 21 with the respective anti-rotation element 4, which engages in a corresponding receptacle on the planet carrier 21, as described. With the disc side 3 each thrust washer 1 is consequently positioned adjacent to the corresponding side surface 22 of the planetary carrier 21 . The opposite disk surface 2, on the other hand, is positioned directly adjacent to the end surface 23 of the planetary wheel 18, which means that the end surface 23 is adjacent to the oil guide grooves 6 and runs against the disk surface 2 in the event of start-up.

Both the roller bearing 19 and the axial contact surfaces of the thrust washers 1 and the planet gear 18 must be supplied with oil for lubrication. This is due to the integration of the thrust washer 1 according to the invention from radially outside of the planet wheel and not from the radially inside, as was previously the case with corresponding bore structures in the planetary pin 20 . The shaft 13 is provided with a channel structure comprising an axially extending channel bore 24 from which at least one radial bore 25 which is open towards the sun gear 14 extends. The sun gear 14 in turn is provided with at least one radial bore 26 which is open on the one hand to the radial bore 25 and on the other hand to the planetary gear arrangement. If oil is supplied via the channel structure in the shaft 13 , the oil leaves this and enters a distributor space 27 between the shaft 13 and the sun wheel 14 . From there, the oil flows on the one hand to the radial bore or bores 26 and, as it were, reaches the left-hand area of the planetary gear arrangement. On the other hand, the oil flows to the axial bearing 15 and radially through it, so that it reaches the right-hand area of the planetary gear arrangement. As the sun gear 14 rotates, the oil is driven radially in the direction of the planetary gear assembly with a certain pressure due to centrifugal force.

As described, the oil guide grooves 6 are open radially on the outer contour 7 as well as on the inner circumference. The oil flowing in from the sun gear 14 can now enter the adjacent oil guide groove 6 or the various oil guide grooves 6 distributed around the circumference, with this entry area being relatively wide due to the V-shaped geometry, so that a correspondingly large quantity of oil can be collected. The respective end faces 23 of the planet wheel are only positioned at a minimal axial distance from the side of the disk 2 or are in contact with it when starting up. This means that the oil guide grooves 6 are more or less closed axially via the end faces 23, so that ultimately corresponding oil guide channels are formed between the respective thrust washer 1 and the end face 23 of the planet wheel 18, which have a radially inwardly tapering geometry.

The oil discharged from the sun gear 14 flows at least into the adjacent pocket 11, from where, after the pocket 11 only moves at the reduced speed of the planet carrier 21, it also flows radially inwards to a certain extent and through the gap on the inner circumference of the thrust washer 1 to the planet pin 20 can flow out.

The configuration of the thrust washer 1 shown in Figures 1 and 2 shows a symmetrical segmentation of the sides of the washer, after the oil guide grooves 6 are distributed equidistantly around the circumference and all have the same V-shape in terms of width, i.e. the same geometry. Of course, it is also conceivable for the oil guide grooves 6 to have different parts Execute width profile, with the width of the oil guide groove 6 and the ultimate nozzle width or the channel volume is influenced and therefore the oil flow. A defined flow of oil can also reduce the axial play of the thrust washer via the oil cushion that builds up.

As described, the thrust washer 1 is produced by forming or deep-drawing and/or embossing a thin metal strip to form the corresponding surface profiles. As a result of the forming and/or the openings to form the oil-guiding grooves, the result after the forming is a corresponding disk width that is wider than the initial width of the original metal strip. This means that a defined final pane width can be set by forming, using a very thin metal strip, which is advantageous in terms of both material consumption and weight. In addition, the overall width of the thrust washer 1 can be varied and adapted to the actual installation space conditions by the corresponding penetration depth, i.e. the variation of the depth of the oil guide grooves 6, so that the thickness of the washer can be easily adapted in relation to a desired, permissible axial play or corresponding tolerances is possible.

Each oil-guiding groove 6 has two groove sections 6a, 6b which are formed as mirror images of one another and are identical to an imaginary line of symmetry S1 or S2. The axes of symmetry S1 and S2 intersect on the central axis M of the thrust washer 1 , the central axis M being the axis of symmetry of the thrust washer 1 at the same time, subject to the different geometry on the anti-rotation element 4 .

The thrust washer 1 has an overall thickness T which is greater than the initial thickness t of a metal sheet from which the thrust washer 1 is made. The total thickness T is an axial dimension between the axially most protruding contours of disk sides 2 and 3. The most protruding contours are at least on one side through the contact surfaces 10a lying in a common radial plane, which are in contact with the planetary carrier 21 or in sliding contact with the planet wheel 23. The axial groove depth of the oil guide groove 6 is described over its entire course from the through hole H to the outer contour 7 of the thrust washer 1 and between two opposing walls W by an axial depth dimension d that remains constant over the course, i.e. the oil guide groove 6 is, subject to rounded edges the walls W of the oil guide groove 6 everywhere the same depth. The axial depth d corresponds to a difference between the total thickness T of the thrust washer 1 and a sheet metal thickness tx that is constant in the radial course from the through-hole H to the outer contour 7 . The sheet metal thickness tx is a distance which is axially between the groove base GG of the oil guide groove 6 and the respective side of the disc facing away from the oil guide groove 6 or 3.

The respective anti-rotation element 4 can advantageously be punched or cut out on the thin sheet metal or sheet metal strip already in the blank, because at the outer open end, i.e. in the flat area in the almost initial state with the initial sheet metal thickness (initial thickness t) of the sheet metal material, at least one of the oil guide grooves 6 of the finished thrust washer (1) and is therefore hardly or not at all changed in its geometry during the molding process of the oil guide grooves 6.

The two thrust washers 1 used per planet wheel 18 are preferably identical, so that identical parts can be used, which is advantageous both in terms of production and assembly.

Reference character list

thrust washer

disc side

anti-rotation element

mounting hole

oil guide groove

outer contour

inner circumference

radial recess

Section a contact surfaces

Bag

planetary gear

Wave

sun gear

thrust bearing

gearing

planet wheel

roller bearing

planet bolt

planet carrier

side face

face

channel drilling

radial bore radial bore

distribution room d Depth dimension of the groove depth of the oil guiding groove

EH inner end of the oil guide groove

E7 End of the oil guide groove on the outer contour of the thrust washer

H Clearance hole in thrust washer

M center axis of thrust washer

51 line of symmetry

52 Line of symmetry t initial thickness of a metal sheet tx sheet thickness between the bottom of the groove and the opposite side of the pane

T Total thickness of thrust washer

W Walls of oil guide groove

Claims

Thrust washer with a central, axial through-hole (H) and with two disc sides (2, 3) facing away from each other, wherein at least one of the disc sides (2, 3) is provided with at least one radially extending oil guide groove (6), the oil guide groove (6 ) are formed circumferentially between contact surfaces (10a) pointing in the axial direction on the at least one disc side (2, 3) and wherein the oil guide groove is open towards the outer contour (7) of the thrust washer (1) and towards the through hole (H), with radially is directed transversely perpendicular to an axially aligned central axis (M) of the thrust washer (1), and wherein the oil guide groove (6) is wider at its end (E7) ending at the outer contour (7) than at the through hole (H) ending inner end (EH ) are, wherein the oil guide groove (6) in each case opens into a radial recess (9) provided on the inner circumference (8), characterized in that a. each oil-guiding groove (6) has two groove sections (6a, 6b) which are mirror-inverted in relation to an imaginary line of symmetry (S1, S2), b. the thrust washer (1) has a total thickness (T) which is greater than the initial thickness (t) of a metal sheet, the total thickness (T) being an axial dimension between the axially most protruding contours of the sides of the disk (2, 3) and being the thrust washer (1) is formed from sheet metal, c. the axial groove depth of the oil guide groove (6) is described over its entire course from the through hole (H) to the outer contour (7) of the thrust washer (1) and between two opposing walls (W) by an axial depth dimension (d) that remains constant over the course , wherein the axial depth dimension (d) is a difference between the total thickness (T) of the thrust washer (1) and a sheet metal thickness (tx) that is constant in the radial course from the through hole (H) to the outer contour (7), and wherein the sheet metal thickness ( tx) is a distance which exists axially between the groove base (GG) of the oil guide groove (6) and the side of the disc (2, 3) facing away from the oil guide groove (6).

2. Thrust washer according to claim 1, characterized in that the sheet metal thickness (tx) corresponds to the initial thickness (t) of the sheet metal.

3. thrust washer according to claim 1, characterized in that the walls (W) are mirror images of each other formed geometrically identical.

4. thrust washer according to claim 1, characterized in that at least three oil guide grooves (6) and radial recesses (9) are provided equidistantly distributed around the circumference.

5. thrust washer according to claim 1 or 2, characterized in that with several oil guide grooves (6) all oil guide grooves (6) have the same geometry and the same course, or that oil guide grooves (6) of different geometry with different widths are provided.

6. thrust washer according to claim 1, characterized in that an anti-rotation element (4) is provided which protrudes from one side of the disc (3) and the end (E7) of an oil guide groove (6) is located radially opposite.

7. thrust washer according to claim 1, characterized in that at least one of the disc sides (2, 3) is provided with an anti-wear coating.

8. planetary gear (12) with at least one thrust washer (1) according to claim 1, in which the thrust washer (1) between a planet gear (18) and a planet carrier (21) of the planetary gear (12) is arranged, wherein at one to the planet gear ( 18) facing disk side (2), one or more radially extending oil guide grooves (6) which are open radially on the outer contour (7) and on the inner circumference (8) of the thrust washer (1), are provided, characterized in that the the planet carrier (21) of the planetary gear (12) cooperating anti-rotation element (4) on the - 18 -

Outer contour (H) ending end (E7) of at least one of the oil guide grooves (6) is formed. Planetary gear (12) according to claim 8, characterized in that a toothing (16) having a sun wheel (14) is provided, which meshes with its toothing (16) with the toothed planet wheels (18), the sun wheel (14) being driven by a central shaft (13), which has a corresponding channel structure through which oil can be supplied, the channel structure having at least one radial bore (25) through which the oil exits radially from the shaft (13) and into the interior of the sun gear ( 14), the sun gear (14) having at least one radial bore (26), the oil exiting radially via the radial bore (26) and flowing radially from the inside to the planet gears (18).