Planetary carrier with direct torque transmission

Abstract

A device (1) is proposed which is provided with a planetary gear set (2) and a bevel gear set (3) with at least one bevel gear (6), wherein the planetary gear set (2) has at least one planet carrier cheek (4) which supports at least one planet gear pin (5), wherein the one planet carrier cheek (4) supports the at least one bevel gear (6), wherein the planet carrier cheek (4) is made of sheet metal.

Description

[0001] The invention relates to a planet carrier with a direct torque transmission from a planetary gear to a bevel gear.

[0002] DE 10 2007 040 479 A1 discloses a differential gear with a sum shaft for distributing torques to a first differential member and to a second differential member via at least one planetary bevel gear, wherein the planetary bevel gear is operatively connected in such a way that the planetary bevel gear is in tooth mesh with a first toothing on the first differential member and with a second toothing on the second differential member, wherein the axis of rotation of the planetary bevel gear is perpendicular to the axis of rotation of the sum shaft and the axis of rotation of each differential member, wherein the sum shaft is designed as a spur gear in which the at least one planetary bevel gear is mounted.

[0003] WO 2020 069 692 A1 discloses a differential with differential gears, a drive gear and at least one cover, wherein the drive gear has external circumferential toothing around an axis of rotation and is provided with bearing points on the inside, the differential gears are mounted at the bearing points in the drive gear and the differential is closed on one side with the cover, wherein the differential gears are held in the drive gear by means of the cover and that the cover and the drive gear are attached to each other without the effect of any further fastening means only by at least one material-fit connection in such a way that at least the differential formed from the differential gears, the drive gear and the cover is a self-supporting unit.

[0004] CN 1 18 532 454 A shows a coaxial transmission comprising a reduction unit with a sun gear, several planet gear sets, and a ring gear. Each planet gear set has a first and a second planet gear, which are fixedly connected and rotatable coaxially. A differential unit contains first and second bevel half-shaft gears arranged along the axis, as well as several bevel planet gears arranged circumferentially and each meshing with both half-shaft gears. The reduction unit is mounted on a first planet carrier; the ring gear is located outside the first planet carrier and meshing with the second planet gear. The bevel planet gears are flexibly connected to the second planet gear via the first planet carrier. A second planet carrier is fixedly connected to the first planet carrier, and the differential unit is located between the two carriers.The first bevel gear half-shaft gear lies inside the first planet carrier and overlaps axially completely with the second planet gear.

[0005] US Patent 2023 / 0051028A1 discloses a power transmission device comprising a gear mechanism, an axially overlapping wall section, and a plate positioned between them. A parking lock device is designed such that a parking lock pawl is located on the side of the plate facing the wall, while a manual shaft and / or a detent mechanism is located on the side of the plate facing the gear mechanism.

[0006] WO 2025 / 145 826 A1 shows a wheel drive device with a rotary bearing carrier that has a fitting space. An output gearbox is coupled to the rotary bearing carrier and drives it. A first fixed axle passes through the rotary bearing carrier and is fixed to it by means of a fastening element. Several differential gears are rotatably mounted on the fixed axle and are located within the fitting space.

[0007] The task is to improve an existing gear combination consisting of a planetary gear unit and a bevel gear unit.

[0008] The problem is solved according to the invention by a device with a planetary gear unit and a bevel gear unit with at least one bevel gear, wherein the planetary gear unit has at least one planet carrier cheek which supports at least one planet gear pin, in that the one planet carrier cheek supports the at least one bevel gear.

[0009] The bevel gear transmission is preferably a bevel gear differential, wherein the bevel gear bolts are designed as differential bolts and the housing halves as differential housing halves.

[0010] The advantage of this solution is that the planet carrier web is flat and can therefore be manufactured by stamping. Stamping or other material removal processes allow for the economical creation of one or more recesses to accommodate one or more bevel gears and their bevel gear pins, precisely shaped and positioned to match the components to be used. Ideally, the receptacles for the planet gears of the planetary gear set can also be created simultaneously with the recesses. This results in a planet carrier web where the torque transmission from the planetary gear set to the bevel gear set occurs almost entirely through the material of the planet carrier web itself, without any intervening connection points such as bolts or welds.

[0011] The force applied circumferentially to the planet carrier web by the planet gear pins is transmitted via the planet carrier web according to the invention directly, through the material of the planet carrier web located between two material reliefs, to the bevel gear located circumferentially between two planet gears, or also to its differential pin. In this area and under this load condition, the planet carrier web has a very high area moment of inertia, according to which the torque is transmitted very directly and without further twisting through coupling points to the bevel gear drive. The planet carrier web, with its material relief surface, presses against the differential pin of the bevel gear (or, in the case of a one-piece design of differential pin and bevel gear, against the bevel gear itself).Preferably, the differential pin and bevel gear are designed as two parts to prevent the differential pin from rubbing against the material relief surface due to rotation about its axis of symmetry. For this purpose, the differential pin is secured against rotation within the material relief. The associated bevel gear rotates on the differential pin to perform its function in the bevel gear drive.

[0012] The planet gears of the planetary gear system can be designed as stepped planet gears or unstepped planet gears.

[0013] The bevel gear pins are advantageously supported directly and immediately at both ends on the planet carrier web according to the invention. Alternatively, the bevel gear pin can be supported at only one end in the planet carrier web according to the invention, but advantageously at its radially outer end. It is also possible to have a bevel gear pin formed integrally with the bevel gear, which in turn is supported and mounted either at both ends or only at one of its ends in the planet carrier web according to the invention.

[0014] Since the planetary carrier web according to the invention, with its material reliefs, lacks axial retention to prevent the inserted bevel gear pins from falling out, the two housing halves of the bevel gear unit can provide axial retention on both sides by axially overlapping the bevel gear pin inserted into the planetary carrier web according to the invention on one side each. Because a housing half is mounted with the planetary carrier web on each axial side, each housing half limits one axial direction of the material relief and thus locks the axial degree of freedom of the bevel gear pin.

[0015] Alternatively, instead of the housing half, a separate component can be provided, for example in the form of a bracket which covers the material relief in the axial direction, so that one axial degree of freedom of the bevel gear pin is blocked and the bevel gear pin remains reliably in the material relief.

[0016] A rotation lock for a bevel gear bolt that is designed separately from the bevel gear can be formed either via the housing half or via the aforementioned alternative of the bracket.

[0017] In an advantageous embodiment of the invention, the bearing of the at least one bevel gear is either the bevel gear itself or comprises the bevel gear with its bevel gear pin. The bevel gear can thus rotatably sit on a bevel gear pin, the bevel gear pin being inserted in the material recess of the planet carrier web.

[0018] In a further development, the bearing of at least one bevel gear and / or its differential bolt is formed by a material relief of the planet carrier cheek.

[0019] In a detailed embodiment of the invention, the planet carrier web is positioned between two housing halves, each of which contacts an axial surface of the planet carrier web. This ensures that the material clearance is axially covered on both sides, and the planet carrier web can be joined between the two housing halves of the bevel gear unit to form a single component. The connection between the housing halves and the planet carrier web is preferably implemented as a bolted connection using screws.

[0020] In one embodiment, the bevel gear or its bevel gear pin, held in the bearing, is axially secured by at least one housing half of the bevel gear unit flanking the planet carrier web. If both housing halves are positioned on either side of the planet carrier web – forming a sandwich arrangement with one housing half on each axial side of the planet carrier web – each housing half can provide axial securing for the bevel gear or its bevel gear pin held in the bearing.

[0021] In an alternative embodiment, the bevel gear or its bevel gear pin, held in the bearing, is axially secured by at least one bracket flanking the planet carrier web. The bracket can be formed separately from the housing half or as an integral part of it. The separately formed bracket can be connected to the housing half, in which case the housing half is connected to the planet carrier half, or the separate bracket can be directly connected to the planet carrier half.

[0022] Furthermore, the planet carrier web has a receptacle for a bolt of the stepped gear from the planetary gear set, which is positioned on the bisector of the angle between two bevel gear bearings. The receptacle is designed as a circular through-hole, and the bolt of the stepped gear inserted therein is secured against rotation by a rivet in the planet carrier web.

[0023] Another design provides that the connection of the axially securing components consisting of the bracket and / or housing half is formed by a screw connection or a welded connection.

[0024] Preferably, the planet carrier cheek is made of sheet metal. Sheet metal construction is advantageous because the material cutouts can be easily and economically cut from the sheet metal by punching.

[0025] The planet carrier web is particularly favorably positioned to hold exactly three bevel gears. Character description

[0026] Further embodiments of the invention are explained in more detail with reference to the figures. They show: Fig. 1 a device with a planetary gear drive and a bevel gear drive as well as the planetary carrier cheek according to the invention in section, Fig. 2 the device according to Fig. 1 in a perspective view, Fig. 3 the device according to Fig. 2 in a perspective view without one differential housing half, Fig. 4 the device according to Fig. 1 on average without gears and Fig. 5 the device according to Fig. 4 in a perspective view.

[0027] The Fig. Figure 1 shows a device 1 with a planetary gear set 2 and a bevel gear set 3, as well as the planet carrier web 4 according to the invention, in section. The planetary gear set 2 has several—in this embodiment exactly three—stepped gears 14 distributed around the circumference as planet gears, each of which is rotatably mounted on its own planet gear pin 5. Each planet gear pin 5 is non-rotatably received in a receptacle 15 provided specifically for this purpose in the planet carrier web 4 of the planetary gear set 2. The planet carrier web 4 according to the invention also has several—in this embodiment exactly three—material cutouts 16 evenly distributed around the circumference, which are more clearly visible in the further illustrations of the remaining figures. These material cutouts 16 have a closed geometry in the form of a window, with an uninterrupted circumferential surface.Each material recess 16 serves to support a bevel gear 6 and / or its bevel gear pin 7. The bevel gear pin 7 is in direct contact with its material recess 16, while the associated bevel gear 6 – in this embodiment – ​​is rotatably mounted on its bevel gear pin 7. Thus, the bevel gear 6 is indirectly supported in the material recess 16 via the bevel gear pin 7.

[0028] An alternative to this is that the bevel gear pin 7 and its bevel gear 6 can be formed in one piece, whereby the bevel gear pin 7 can then be rotatably received about its axis of symmetry within the material clearance 16 and thus the bevel gear 6 formed in one piece with the bevel gear pin 7 is directly supported.

[0029] The embodiment shown is Fig. 1 further comprises a bevel gear transmission 3 designed as a bevel gear differential, which includes several – in this embodiment exactly three – bevel gears 6 enclosed by two housing halves 8 and 9 of the bevel gear transmission 3. In the usual manner, the bevel gears 6 mesh with the output bevel gears, which are rotationally fixed to the output shafts (output bevel gears and output shafts not shown).

[0030] In the illustrated embodiment, the bevel gears 6 have no contact with the planet carrier cheek 4 according to the invention, since a spherical disk is placed between each bevel gear 6 and the housing halves 8 or 9.

[0031] The two housing halves 8 and 9 flank the planet carrier cheek 4. One housing half 8 rests against one axial surface 10 of the planet carrier cheek 4, and the other housing half 9 rests against the other axial surface 11 of the planet carrier cheek 4, which is located on the side of the planet carrier cheek 4 opposite the axial surface 10. The housing halves 8 and 9 are screwed together by means of several screws 17 (more clearly visible in the other figures), with the planet carrier cheek 4 clamped centrally between the two housing halves 8 and 9. A bridge 12 is formed circumferentially between two screws 17 of each housing half 8 and 9, which axially covers the material relief 16 and axially fixes or secures the bevel gear pin 7. In addition, each bridge 12 is in contact with the anti-rotation surface 18 of the bevel gear bolt 7 in order to prevent the bevel gear bolt 7 from rotating about its longitudinal axis.

[0032] The Fig. Figure 2 shows the device 1 after Fig. 1 in a perspective view.

[0033] Further explanations regarding the Fig. Figure 1 clearly shows that a bridge 12 is formed between two circumferentially successive screws 17, which axially covers the material clearance 16. In this embodiment, both housing half 8 and housing half 9 form a bridge 12 that is integrally formed with the respective housing half 8 or 9. Alternatively, the bridge 12 can be formed separately from the housing half 8 or 9.

[0034] It is also visible that the bridge 12 is bulged in the axial direction. The bulge points away from the bevel gear pin 7 and thus reduces the axial dimension of the planet carrier cheek 4. In other words, although the bevel gear pin 7 is located within the material clearance 16, it projects axially beyond the axial surfaces 10 and 11 – however, it is contacted by the bridge 12(s) by contacting the anti-rotation surfaces 18 and is thus fixed axially.

[0035] If a torque is applied from the planetary gear set 2 via the stepped gears 14 to the planet carrier web 4, the circumferential force can be transmitted via the planet carrier web 4 directly to the bevel gear pins 7 located in the material recesses 16 and thus subsequently to the bevel gears 6. A particular advantage is that the circumferential force exhibits no axial offset and therefore exerts virtually no bending moment on the material of the planet carrier web 4 in the area between a receptacle 15 and a material recess 16 immediately following it in the circumferential direction. This area is thus subjected almost exclusively to compressive or tensile stress.

[0036] The Fig. 3 shows the device after Fig. 2 in a perspective view without one differential housing half.

[0037] The hidden housing halves 8 and 9 now allow a view of the bevel gears 6 and bevel gear pins 7 placed in the material cutouts 16. The anti-rotation surfaces 18 formed by the bevel gear pins 7 are clearly visible and are in contact with at least one of the bridges 12 (not shown here) to ensure that the bevel gear pin 7 is not rotated.

[0038] The embodiment now also shows a clear view of the bores through which the screws 17 penetrate (see illustrations of the Fig. 1, Fig. 2, Fig. 4 and Fig. 5).

[0039] The bridge 13 separates the pockets for the stepped gears 14 from each other on the circumferential side of the planetary gear 2 and stabilizes the planet carrier of the planetary gear 2.

[0040] The Fig. 4 shows the device after Fig. 1 on average without gears.

[0041] The two housing halves 8, 9 are advantageously designed as drawn sheet metal half-shells and are screwed together by means of the screws 17. Alternatively, instead of screwing, each housing half 8, 9 can be welded to the planet carrier side 4, or the screw connection can be replaced by riveting. As an alternative to sheet metal construction of the housing halves 8, 9, a casting in aluminum is also possible.

[0042] The Fig. 5 shows the device after Fig. 4 in a perspective view.

[0043] The webs 13 can be welded to the planet carrier cheek 4. Advantageously, the screws 17 engage in a thread in one of the housing halves 8, 9. The thread may already be formed in the housing half 8 or 9, or the screws 17 may be designed as self-tapping screws and cut the thread into the respective housing half 8, 9 during the screwing process. Reference symbol list 1 Device 2 planetary gear sets 3 bevel gear sets 4 planetary carrier cheek 5 planetary gear bolts 6 bevel gear 7 bevel gear bolts 8 Housing half 9 Housing half 10 Axial area 11 Axial area 12 hangers 13 Bridge 14-step gear 15 recording 16 Material exemption 17 screw 18 Anti-rotation surface

Claims

[1] Device (1) with a planetary gear set (2) and a bevel gear set (3) with at least one bevel gear (6), wherein the planetary gear set (2) has at least one planet carrier web (4) which supports at least one planet gear pin (5), which supports the at least one bevel gear (6), characterized by , that the planet carrier cheek (4) is made of sheet metal. [2] Device (1) according to claim 1, characterized by , that the bearing of the at least one bevel gear (6) comprises either the bevel gear (6) itself or the bevel gear (6) with its bevel gear pin (7). [3] Device (1) according to any one of the preceding claims, characterized by , that the bearing is formed by a material release of the planetary support cheek (4). [4] Device (1) according to any of the preceding claims or according to the preamble of claim 1, characterized by, that the planet carrier cheek (4) is placed between two housing halves (8, 9), each of which contact an axial surface (10, 11) of the planet carrier cheek (4). [5] Device (1) according to any of the preceding claims or according to the preamble of claim 1, characterized by , that an axial securing of the bevel gear (6) received in the bearing or of its bevel gear bolt (7) is formed by at least one housing half (8, 9) of the bevel gear drive (3) flanking the planet carrier cheek (4). [6] Device (1) according to any one of the preceding claims, characterized by , that an axial securing of the bevel gear (6) received in the bearing or of its bevel gear bolt (7) is formed by at least one bracket (12) flanking the planet carrier cheek (4). [7] Device (1) according to any one of the preceding claims, characterized by, that the planet carrier cheek (4) has a receptacle (15) for the planet gear bolt (5) of the stepped gear (14) of the planet gear drive (2), which is placed on the angle bisector of two bevel gear bearings. [8] Device (1) according to one of claims 5 or 6, characterized by , that the connection of the axially securing components consisting of bracket (12) and / or housing half (8, 9) is formed by a screw connection or a welded connection. [9] Device (1) according to any of the preceding claims, characterized by , that the planet carrier cheek (4) supports three bevel gears (6).

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