Planetary gear with planet bolts fixed in a planet carrier via hollow rivets

Abstract

Planetary gear (1) for a motor vehicle drive, comprising a planet carrier (2) and a planet bolt (3) attached to the planet carrier (2), wherein the planet bolt (3) is attached to the planet carrier (2) by means of a pin (5) oriented transversely to it and received in a receiving hole (4) provided in it, characterized in that the pin (5) radially penetrates the hollow planet bolt (3) and is pressed into a position securing the planet bolt (3) relative to the planet carrier (2) by a ring body (6) pressed into the planet bolt (3).

Description

[0001] The invention relates to a planetary gear, preferably designed as a differential gear, for a motor vehicle drive, i.e., a drive / drivetrain of a motor vehicle such as a car, truck, bus, or other commercial vehicle. The planetary gear comprises a planet carrier and a planet bolt attached to the planet carrier. The planet bolt is attached to the planet carrier by means of a pin, which pin is oriented transversely to the planet bolt and is received in a receiving hole provided in the planet bolt.

[0002] Planetary gear systems of this type are already well known from the prior art. For example, US 2005 / 0130790 A1 discloses a planetary gear system with a planet carrier and bolt-like bearing elements for receiving planet gears.

[0003] Securing the planetary bolts with separate elements means that, compared to conventional fastening methods such as riveting areas of the planetary bolt and / or the planetary carrier, no special machine tools are required for this fastening, but it increases the complexity of manufacturing and assembly.

[0004] DE 10 2014 225 340 A1 discloses a planetary gear with several planet gears that interact with a central sun gear. Each of these gears is rotatably mounted on a planetary journal of a single-walled planet carrier via an associated planetary bearing, the planetary journal being pressed into a corresponding receiving bore of the planet carrier. The pressed-in planetary journal has at least one transverse bore that opens into the inner wall of the receiving bore and accommodates clamping means for fixing the planetary journal to the planet carrier.

[0005] DE 10 2015 209 254 A1 discloses a gear shaft retention and lubrication system consisting of a gear shaft extending along an axis and carrying a gear. The gear shaft has a first radial bore extending radially from the outer surface of the shaft, at least partially through the shaft. The gear shaft also has a second radial bore, likewise extending radially from the outer surface and axially aligned with the gear. Furthermore, the gear shaft includes an axial bore of a specific diameter, extending axially through the gear shaft and through the first and / or second radial bore.

[0006] The system also includes a mounting surface which partially contains an opening in the axial direction for receiving the gear shaft and a first mounting surface radial bore which is coaxial to the first shaft radial bore and extends from the opening through at least a part of the mounting surface.

[0007] A fastening element, consisting of a head and a shaft, is partially arranged within the shaft's axial bore. Furthermore, an annular gap is formed between the shaft's axial bore and the fastening element's shaft in the radial direction, and between the first and second shaft radial bores in the axial direction.

[0008] DE 29 25 964 A1 discloses a lubricant supply device for receiving pressurized lubricant from a lubricant supply system and delivering it to a device to be lubricated. This lubricant supply device comprises: a supply device for receiving the pressurized lubricant from the lubricant supply system; a chamber rotatable about a rotary axis, functionally connected to the supply device and receiving pressurized lubricant via it; a distributor structure rotatable together with the chamber and located radially outside the supply device; a passage between the supply device and the distributor structure for transmitting the pressurized lubricant from the supply device to the distributor structure; and an outlet structure extending from the distributor structure that delivers the lubricant to the device to be lubricated.and a chamber outlet metering device between the chamber and the distributor structure, which ensures that a small proportion of the total amount of lubricant supplied by the feed device is fed to the distributor structure while the lubricant is fed under pressure from the feed device into the chamber and the passage. The chamber outlet metering device is arranged radially outside the axis of rotation and radially outside the passage in the chamber, so that when the pressurized lubricant supply to the feed device ceases, any lubricant in the chamber is pumped by centrifugal force through the chamber outlet metering device to the distributor structure and further to the outlet structure.

[0009] DE 37 06 212 A1 discloses a planet gear bolt that can be inserted into the carrier of a planetary gear unit. The bolt has a rotationally symmetrical opening at its end that widens conically outwards. A head piece with a counter-cone can be inserted into this opening, extending at least part of the circumference of the planet gear bolt by the conical portion of the opening. The head piece has a threaded stud at its end that is inserted into the opening, which can be screwed into a subsequent threaded bore. This bore follows the conical opening of the planet gear bolt. The end face of the head piece, which lies axially outside the planet gear bolt, is equipped with an internal hexagon socket.

[0010] DE 10 2017 129 359 A1 discloses an arrangement with a press comprising two components and at least one clamping element, which can be inserted radially in the axial direction between a region of the first component and a region of the second component via an axially displaceable actuating element of the press. The actuating element extends axially through both the components and the clamping element. At one end, the actuating element interacts with the actuator, and at the other end, it is provided with a cover element through which it is operatively connected to the components. The clamping element is arranged either between the cover element and the components or between the components and a housing region of the actuator. The actuating element or the actuator is movable to insert the clamping element between the components to a extent that reduces the axial distance between the cover element and the housing region of the actuator.

[0011] DE 10 2016 012 978 A1 discloses a planetary gear unit with a planet carrier and a planet gear shaft, wherein a portion of the planet carrier is formed as a first web. The first web has an axially extending recess into which the planet gear shaft is at least partially inserted. An axially oriented threaded bore is provided in the end face of the planet gear shaft, into which a screw is screwed. This screw connection pre-tensions a spring element, which provides additional security for the connection between the screw and the planet gear shaft. The area axially covered by the screw overlaps at least with the axial area covered by the recess. The spring element is thus pre-tensioned and / or presses against the wall of the recess.

[0012] JP H05-296216A shows a device in which an axle and a support element penetrate a shaft hole, into which the shaft is inserted. Within the riveting structure of this shaft, where the shaft hole and the round hole are drilled on the same axis, is a steel ball with a slightly larger diameter than the round hole. This steel ball is inserted into the round hole of the axial bore and pressed against the axis of the shaft support element. This pressing action creates a compression zone encompassing the shaft hole, the peripheral surface of the shaft, and the enlarged diameter of the shaft. The area of ​​the riveting structure's round bore allows the steel ball to seal the round hole, thereby securing the shaft structure.

[0013] JP H08-14369A shows a planetary gear rotary support device comprising: a support plate, a first round hole formed in this support plate, a support shaft whose base end sits in the first round hole, a connecting plate, and a second round hole formed in the connecting plate that receives the front end of the support shaft. The support shaft has a cylindrical inner ring track in the central outer circumferential region, a toothed ring track on the outside, and a cylindrical outer ring track on the inside. A planetary gear set is rotatably mounted about the support shaft and is meshed with an outer gear and an inner sun gear. Several rollers are arranged to roll between the inner and outer ring tracks.Inside the carrier plate and the support shaft are interconnected oil supply channels. These channels are connected at one end to a passage in the support shaft and at the other end open into the outer circumferential surface of the central section of the support shaft. At one end of the support shaft is a distribution hole extending transversely through the shaft and connected to the oil supply channels. In one of the plates—either the carrier plate or the connecting plate—is an insertion hole extending transversely through the support shaft. The inner end of this insertion hole is exposed in either the inner surface of the first or the second round hole. A pin is inserted into the insertion hole, and its inner end is pushed into the distribution hole. The inner diameter of the distribution hole and the insertion hole is larger than the outer diameter of the pin's body section.At the outer end of the pin is an elastically deformable area whose diameter increases towards the outer end and whose maximum diameter in the free state is larger than the inner diameter of the insertion hole. These properties characterize the planetary gear rotary support device.

[0014] The object of the present invention is therefore to provide a planetary gear unit whose manufacture and assembly are to be made even more efficient.

[0015] This is solved according to the invention by the pin radially penetrating the hollow planetary bolt and being pressed into a position that secures the planetary bolt relative to the planetary carrier by a ring body pressed into the planetary bolt.

[0016] The ring body provides a locking element that can be easily connected to the planetary bolt using simple machine tools, preferably via standard riveting processes. Due to the ring body's special design, its axial insertion into the planetary bolt directly (via the pin) secures it to the planet carrier. This eliminates the need for specialized machine tools for manufacturing and assembling the planetary gear components and significantly reduces assembly effort.

[0017] Further advantageous embodiments are claimed in the dependent claims and are explained in more detail below.

[0018] Therefore, it remains advantageous if the ring body has a conical contact surface that aligns with one end of the pin. This further simplifies the press-fit process.

[0019] If the ring body is even used to act on several pins distributed in a circumferential direction of the planetary bolt (simultaneously) / press into the planet carrier, the assembly process is further simplified.

[0020] It is also advantageous if several ring bodies are pressed into the planetary bolts, each secured by at least one pin. This results in a particularly stable fixing of the planetary bolts.

[0021] If the ring bodies have a uniform inner diameter, the riveting process is further simplified, since a shaft section connected to the two ring bodies during pressing can then be easily pulled out to an axial side of the planetary bolt after assembly.

[0022] The structure is further simplified if one end of the pin, facing away from the ring body, is pressed into a material of the planet carrier.

[0023] Furthermore, it is advantageous if the pin rests against or is pressed into a bridge area of ​​the planet carrier. This eliminates the need for separate recesses in the planet carrier to secure the pin.

[0024] If the ring body is designed as part of a hollow rivet, it is easy to manufacture and can be easily inserted using known riveting processes.

[0025] Furthermore, the invention relates to a method for assembling a planetary gear according to the invention in at least one of the embodiments described above. First, a planetary bolt is positioned in its intended end position in a planetary carrier, and a pin is inserted into a receiving hole radially penetrating the planetary bolt. Subsequently, a hollow rivet, having a ring body, is pressed or drawn axially into a (central) through-hole of the planetary bolt, while simultaneously pressing the pin into the planetary carrier. An axial pressing movement of the ring body thus results in the pin being radially pressed into the planetary carrier.

[0026] Regarding the procedure, it is further advantageous if a section of the hollow rivet shaft is automatically separated from the ring body during the pressing-in process and subsequently removed from the planetary bolt. This significantly simplifies the assembly process.

[0027] The invention will now be explained in more detail below with reference to figures, in which context various embodiments are also indicated.

[0028] They show: Fig. 1 a schematic longitudinal section view of a planetary gear according to the invention in the area of ​​its planet carrier, wherein the fixing of a planet bolt to the planet carrier via several pins can be seen in detail, as well as Fig. 2 another longitudinal section view of the planetary gear according to Fig. 1, showing an assembly process of two ring bodies interacting with the pins.

[0029] The figures are purely schematic and serve solely to illustrate the invention. The same elements are identified by the same reference symbols.

[0030] In Fig. Figure 1 illustrates in detail a planetary gear 1 according to the invention in the region of a planetary pin 3 of its planet carrier 2. The planetary gear 1 is implemented as a differential gear and is accordingly prepared for use at a suitable location in the drive train of a motor vehicle. The planet carrier 2, also referred to as the differential carrier, preferably accommodates several planet gears of several planetary stages, which transmit torque to the drive wheels of the motor vehicle in the usual manner during operation.

[0031] In Fig. 1. Two web sections 9, also alternatively referred to as cheeks, are visible on the planet carrier 2, arranged axially relative to each other. Several planet bolts 3 are inserted circumferentially between these two web sections 9, each serving to support a planet gear, which is not shown in detail here for clarity. Each planet bolt 3 is received / secured with its axial end sections in a receiving opening 13 / a receiving hole of one of the web sections 9.

[0032] For the sake of completeness, it should be noted that the directional terms used here refer to a longitudinal axis 14 of the planet bolt 3, whereby axial / axial direction means a direction along / parallel to the longitudinal axis 14 and radial / radial direction means a direction perpendicular to the longitudinal axis 14.

[0033] In Fig. Figure 1 further illustrates the fixing of the respective planetary bolt 3 in the planetary carrier 2. It can be seen that the planetary bolt 3 is fixed in each web area 9 by means of at least one pin 5. The pin 5 is received with its largest part (longitudinal section) in a radially extending receiving hole 4 that penetrates the hollow planetary bolt 3 (namely, an outer wall area of ​​the planetary bolt 3). The pin 5 is pointed at its radially outer end (second end 7b). The pin 5 projects into / extends into the material of the planetary carrier 2 with a certain section, in particular with positive locking of the planetary bolt 3 relative to the planetary carrier 2 in the axial direction as well as in the direction of rotation / circumference about the longitudinal axis 14.

[0034] The pin 5 is fixed in position at its (first) end 7a, which is opposite the second end 7b. For this purpose, the pin 5 projects radially inwards over the planetary bolt 3 with its first end 7a. In addition, a ring body 6 is present, which is pressed into the planetary bolt 3 and simultaneously pushes the pin 5 (with contact against that first end 7a) radially outwards into the planetary carrier 2.

[0035] The ring body 6 has a circumferential side / radial outer surface that tapers conically in the axial direction, forming a contact surface 8 directly with the pin 5. The axial position of the ring body 6 in the planetary bolt 3 thus fixes the pin 5 in position and simultaneously controls the radial position of the pin 5 and, consequently, the pressing force exerted by the pin 5 on the planet carrier 2. The frictional contact between the contact surface 8 and the pin 5 is self-locking.

[0036] In preferred embodiments, several pins 5 are provided for each web area 9 and planetary bolt 3, connecting the respective planetary bolt 3 to the planetary carrier 2. Thus, a group of pins 5 arranged circumferentially around the planetary bolt 3 is preferably fixed / connected to the planetary carrier 2 by means of a ring body 6.

[0037] Although in this design, as already explained, at least one pin 5 (or several pins 5) is provided for each web area 9 and each planetary bolt 3, it is also possible in alternative designs to provide only one or more pins 5 between the planetary bolt 3 and only one of the two web areas 9.

[0038] In connection with the Fig. 1 and Fig. 2 then shows a preferred assembly method for the respective planetary bolt 3. It is here in Fig. 2. It can be seen that the ring bodies 6 are preferably initially provided as a component of a hollow rivet 10. The hollow rivet 10 then has a (hollow / sleeve-shaped / tubular) shank section 12, to which the ring bodies 6 are integrally formed and project radially outwards.

[0039] In the assembly process, the planetary bolts 3 are inserted into the receiving openings 13 of the planetary carrier 2 in the usual manner. Subsequently, the pins 5 are inserted into the receiving holes 4 of the planetary bolt 3. Following this, the hollow rivet 10, with its preferably integrally molded ring bodies 6, is inserted into the axial through-hole 11 of the planetary bolt 3, such that the respective contact surface 8 contacts the pin 5 at its first end 7a.

[0040] Subsequently, a tensile force is applied to the hollow rivet 10, which, due to the inclined contact surface 8, exerts a compressive force on the pin 5 in a radial outward direction. This pin 5 is thereby pressed into the material of the planet carrier 2, ultimately fixing the planet bolt 3 relative to the planet carrier 2.

[0041] Finally, the ring bodies 6 preferably shear off from the shaft section 12, and the shaft section 12 is removed from the planetary bolt 3. The ring bodies 6 preferably remain in the planetary bolt 3 together with the pins 5.

[0042] In other words, according to the invention, the function of a hollow rivet 10 is incorporated into the planetary bolt 3 / differential bolt.

[0043] This unit is then delivered to the line. Thus, part of the assembly tool is directly integrated into the planetary bolt 3.

[0044] A quality-assuring advantage is that the design of the tool (Morse taper) creates a self-locking friction-fit connection.

[0045] Optionally, it should be noted that the hollow rivet fastening can be done on the left and right or only on one side.

[0046] Furthermore, hollow rivet pulling can be done from one or both sides (in Fig. 2. Pull unilaterally to the right; force F) is applied. The rivet could also be pushed through.

[0047] Assembly procedure: Place planet carrier 2 in tool / holder; insert planet bolt 3 (with hollow rivet 10 / rivet and pins 5 / pre-assembled) with gear / thrust washers (partially not visible); tighten rivet with force; Morse taper (ring body 6) presses pins (preferably several around the circumference) into the softer planet carrier 2; the shank (shank section 12) of the rivet breaks off (predetermined breaking point) and is removed. Reference symbol list 1 planetary gear 2 planetary carriers 3 planetary bolts 4 mounting holes 5 pens 6 ring bodies 7a first end of the pen 7b second end of the pen 8 Contact area 9 Pier area 10 hollow rivets 11 Through hole 12 shaft section 13 Intake opening 14 Longitudinal axis

Claims

[1] Planetary gear (1) for a motor vehicle drive, comprising a planet carrier (2) and a planet bolt (3) attached to the planet carrier (2), wherein the planet bolt (3) is attached to the planet carrier (2) by means of a pin (5) oriented transversely to it and received in a receiving hole (4) provided in it, characterized by , that the pin (5) radially penetrates the hollow planet bolt (3) and is pressed into a position securing the planet bolt (3) relative to the planet carrier (2) by a ring body (6) pressed into the planet bolt (3). [2] Planetary gear (1) according to claim 1, characterized by , that the ring body (6) has a conical contact surface (8) that is in contact with one end (7a) of the pin (5). [3] Planetary gear (1) according to claim 1 or 2, characterized by , that the ring body (6) acts upon several pins (5) distributed in a circumferential direction of the planetary bolt (3). [4] Planetary gear (1) according to any one of claims 1 to 3, characterized by , that several ring bodies (6) are pressed into the planetary bolt (3), each with at least one pin (5) being secured. [5] Planetary gear (1) according to claim 4, characterized by , that the ring bodies (6) have a uniform inner diameter. [6] Planetary gear (1) according to any one of claims 1 to 5, characterized by , that an end (7b) of the pin (5) facing away from the ring body (6) is pressed into a material of the planet carrier (2). [7] Planetary gear (1) according to any one of claims 1 to 6, characterized by , that the pin (5) rests against a bridge area (9) of the planet carrier (2). [8] Planetary gear (1) according to any one of claims 1 to 6, characterized by , that the ring body (6) is formed as part of a hollow rivet (10). [9] Method for assembling a planetary gear (1) according to any one of claims 1 to 7, wherein a planet bolt (3) is first arranged in its intended end position in a planet carrier (2) and a pin (5) is inserted into a receiving hole (4) radially penetrating the planet bolt (3), and thereafter a hollow rivet (10) having a ring body (6) is pressed or drawn axially into a through hole (11) of the planet bolt (3), while simultaneously pressing the pin (5) into the planet carrier (2). [10] Method according to claim 9, characterized by , that a shaft section (12) of the hollow rivet (10) is automatically separated from the ring body (6) during the pressing process and is subsequently removed from the planetary bolt (3).

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