Gear arrangement

Abstract

A transmission arrangement for transmitting the drive power of a motor vehicle, comprising an intermediate shaft (1) supported on both sides by a rolling bearing (2, 3), on which at least a first gear (7) and a second gear (13) are arranged to form a gear stage, wherein the first gear (7) has a larger diameter than the second gear (13) and can be detachably fitted onto the intermediate shaft (1) via a shaft-hub connection, wherein in the assembled state a first gear side surface (8) of the first gear (7) comes into contact with a stop shoulder (9) of the intermediate shaft (1), wherein to secure the detachable connection of the first gear (7) with the intermediate shaft (1) an annular lock nut (10) is provided, which can be screwed onto an external thread (15) on the intermediate shaft (1) via an internal thread (16) and which cooperates with it and is axially adjacent to the shaft-hub connection.that the lock nut (10) in the assembled state is completely received by a corresponding annular disc-shaped recess (11) in a second gear side surface (12) of the first gear (7), characterized in that the lock nut (10) has several recesses (17) on an outer flank side for engagement of a screw tool.

Description

[0001] The invention relates to a gear arrangement for transmitting a drive power of a motor vehicle, comprising an intermediate shaft which is mounted on both sides via a rolling bearing and on which at least a first gear and a second gear are arranged to form a gear stage, wherein the first gear has a larger diameter than the second gear and can be detachably plugged onto the intermediate shaft via a shaft-hub connection, wherein in the assembled state a first gear side surface of the first gear comes to rest on a stop shoulder of the intermediate shaft.

[0002] The field of application of the invention extends primarily to automotive technology. Motor vehicle transmissions usually consist of a plurality of shafts carrying gears, of which there is usually an input shaft, at least one intermediate shaft, and at least one output shaft. An intermediate shaft of the type of interest here is usually supported by roller bearings on both sides and forms at least one gear stage, whereby the gears are either integrally or detachably connected to the shaft in a rotationally fixed manner, or can be secured via, for example, clutches or other mechanisms. If, within the framework of such a transmission arrangement, a gear is detachably mounted on an intermediate shaft via a rotationally fixed shaft-hub connection, the connection must also be secured axially, because helical gears are generally used. The present invention is dedicated to this topic. State of the art

[0003] DE 10 2018 100 649 A1 discloses a transmission arrangement equipped with a Ravigneaux set of gears. Among other things, an output shaft meshes with an intermediate shaft, which further interacts with an axle shaft. Said intermediate shaft comprises a first gear and a second gear, which form a gear stage. For this purpose, both gears are connected to the intermediate shaft in a rotationally fixed manner. The output-side gear has a smaller diameter than the input-side gear.

[0004] Other gear arrangements of this type with gears detachably mounted on a shaft are known from JP 2005 299 864 A, DE 10 2007 039 481 A1 and DE 10 2012 006 633 A1.

[0005] According to the generally known prior art, a snap ring, for example, is used to axially secure a detachable connection of a gear to a shaft. This snap ring is mounted in a circumferential groove on the gear side flank opposite a stop shoulder of the shaft and requires an axial installation space that is at least equal to the groove width. In addition to such detachable securing of a shaft-hub connection, permanent securing devices are also used, such as a press fit or a weld seam that firmly connects the gear to the shaft. In this case, the weld seam can also be concealed within a radial weld seam groove on the relevant gear side flank. This means that although no additional axial installation space is required, the creation of the firmly bonded connection results in a correspondingly higher manufacturing effort.

[0006] It is the object of the present invention to further improve a gear arrangement of the generic type in such a way that a gear wheel which is detachably mounted on an intermediate shaft by means of a shaft-hub connection is axially secured in a manner which is simple in terms of production technology and saves installation space. Disclosure of the invention

[0007] The object is achieved based on a transmission arrangement according to the preamble of claim 1 in conjunction with its characterizing features or the characterizing features of claim 2, as well as according to the features of claim 5. With regard to a motor vehicle comprising the transmission arrangement, reference is made to claim 10. The dependent claims reflect advantageous developments of the invention.

[0008] The invention includes the technical teaching that, to secure the detachable connection of a gear of relatively large diameter to an intermediate shaft, a ring-shaped lock nut is provided, which can be screwed via an internal thread onto a cooperating external thread formed axially adjacent to the shaft-hub connection on the intermediate shaft in such a way that, in the assembled state, the lock nut is completely received by a corresponding ring-shaped recess in the associated gear side surface of the first gear. In other words, the lock nut is completely countersunk into the gear in the axial direction.

[0009] The advantage of the inventive solution lies in the fact that, in addition to the gear width, no additional axial space is required for the gear locking mechanism, i.e., securing the detachable shaft-hub connection. The locking mechanism can be implemented by simply screwing it onto the external thread provided for this purpose on the shaft, which can also be performed as part of an automated production step. In principle, the inventive solution combines a detachable shaft-hub connection for torque transmission with a specially arranged screw connection for securing the connection, which can reliably absorb the high axial forces generated by helical gearing.

[0010] According to a preferred embodiment, the annular disk-shaped nut has a hollow cylindrical envelope geometry, the cylinder height of which is several times smaller than the cylinder's inner and outer diameters. This means that the lock nut is particularly flat, allowing it to be countersunk into gears with a narrow gear width without significantly weakening the shaft-hub connection. Shape deviations such as chamfers, threads, recesses, and the like can be present within the envelope geometry.

[0011] Preferably, the second gear with a smaller diameter should be molded directly onto the intermediate shaft. The gearing only needs to protrude sufficiently beyond the rest of the shaft's outer surface. The intermediate shaft, in combination with this second gear, is preferably designed as a hollow shaft, resulting in a material-saving design consisting of a shaft with a smaller second gear.

[0012] According to a measure further improving the invention, the intermediate shaft is equipped at each end with conical raceway sections, each tapered towards the shaft end, of a preferably tapered roller bearing for the purpose of supporting rolling elements on both sides, on which the rolling elements roll. To achieve a design that saves space in the axial direction, the conical raceway section should be arranged directly axially adjacent to the external thread of the intermediate shaft. At the other end of the intermediate shaft, the raceway section should be arranged directly axially adjacent to the first gear if no further gears or the like are provided. It is also possible to design the shaft ends conventionally cylindrically and to equip them with standard rolling bearings.

[0013] An alternative further measure according to the invention for reducing the axial length consists in forming the stop shoulder for the first, larger gear, which can be attached to the intermediate shaft, directly through the associated flank side of the second gear. As a result, the tooth width of the first gear directly adjoins the tooth width of the second gear.

[0014] The shaft-hub connection between the first gear and the intermediate shaft can be designed in various ways. For example, a positive spline, a tongue-and-groove connection, or the like are possible. Alternatively, the shaft-hub connection can also be non-positive, for example, as a press fit. Combined positive / non-positive connections are also conceivable. Detailed description based on the drawing

[0015] Further measures improving the invention are described in more detail below, together with the description of a preferred embodiment, with reference to the drawing. It shows: Fig. 1 a longitudinal section through a gear arrangement for transmitting drive power, which is designed here in the form of an intermediate shaft, Fig. 2 a perspective view of the intermediate shaft with a gear of smaller diameter formed directly thereon, and Fig. 3 a perspective view of a ring-disk-shaped lock nut for fastening a gear of larger diameter on the intermediate shaft.

[0016] According to Fig. 1 is an intermediate shaft 1 of a gear arrangement (not shown here) designed as a hollow shaft, supported at each end by a rolling bearing 2 and 3. The two rolling bearings 2 and 3 are designed as tapered roller bearings, with the rolling elements 4 (exemplarily) not interacting with the respective bearing inner rings, but rolling directly on raceway sections 5 and 6, respectively, which taper towards the shaft end.

[0017] A first gear 7 is mounted on the intermediate shaft 1 via a detachable, positive-locking shaft-hub connection. In the assembled state shown, a first gear side surface 8 of the first gear 7 rests against a stop shoulder 9 of the intermediate shaft 1.

[0018] To secure the shaft-hub connection of the first gear 7 with the intermediate shaft 1, a ring-disk-shaped lock nut 10 is used, which is screwed onto the intermediate shaft 1 in such a way that, in the assembled state shown, it is completely received by a ring-disk-shaped recess 11 corresponding thereto in the second gear side surface 12 of the first gear 7.

[0019] Directly axially adjacent to the first gear 7 mounted on the intermediate shaft 1 in this manner is a second gear 13, which, unlike the first gear 7, is molded directly onto the intermediate shaft 1, thus forming a single-piece component. In this configuration, the stop shoulder 9 of the intermediate shaft 1 is formed by the flank side of the second gear 13 adjacent to the first gear 7.

[0020] According to Fig. 2, the shaft-hub connection between the gear 7 (not shown here) and the intermediate shaft 1 is realized via a splined section 14 on the shaft 1. The splined section 14 adjoins the said shoulder-forming flank side of the second gear 13 in the axial direction. The conical raceway section 6 adjoins the opposite flank side of the gear 13. The other conical raceway section 5 is located at the opposite shaft end, which in turn is directly adjoined by an external thread 15, which is assigned to the annular disk-shaped lock nut 10 (not shown here).

[0021] According to Fig.3, the ring-shaped lock nut 10 is equipped with an internal thread 16 corresponding to the aforementioned external thread 15. In addition, the lock nut 10 has several recesses 17 on an outer flank side for engagement with a screwing tool (not shown here).

[0022] The invention is not limited to the preferred embodiment described above. Rather, modifications thereof are also conceivable, which are also covered by the scope of protection of the following claims. For example, it is also possible for more than two gears to be arranged on an intermediate shaft following the principle described above. Furthermore, the invention can also be applied to other gear stages that are not tied to an intermediate shaft. Finally, the shaft-hub connection between the gear with a larger diameter and the intermediate shaft can also be designed in a different way, for example as a positive-locking tongue-and-groove connection, a non-positive press connection, or as a combination of a positive-locking and non-positive shaft connection. List of reference symbols 1 intermediate shaft 2 first rolling bearing 3 second rolling bearing 4 rolling elements 5 first career stage 6 second career phase 7 first gear 8 first gear side surface 9 Stop paragraph 10 Lock nut 11 Recess 12 second gear side surface 13 second gear 14 Gear section 15 external threads 16 internal threads 17 Recess

Claims

[1] A gear arrangement for transmitting the drive power of a motor vehicle, comprising an intermediate shaft (1) mounted on both sides by a roller bearing (2, 3) each, on which intermediate shaft (1) at least one first gear (7) and one second gear (13) are arranged to form a gear stage, wherein the first gear (7) has a larger diameter than the second gear (13) and can be releasably attached to the intermediate shaft (1) via a shaft-hub connection, wherein in the assembled state a first gear side surface (8) of the first gear (7) comes to rest against a stop shoulder (9) of the intermediate shaft (1), wherein to secure the releasable connection of the first gear (7) to the intermediate shaft (1) a washer-shaped lock nut (10) is provided, which can be screwed via an internal thread (16) onto an external thread (15) cooperating therewith and formed axially adjacent to the shaft-hub connection on the intermediate shaft (1) in such a way thatthat the locking nut (10) in the assembled state is completely received by a corresponding annular disc-shaped recess (11) in a second gear side surface (12) of the first gear (7), , characterized by that the lock nut (10) has a plurality of recesses (17) on an outer flank side for engagement of a screwing tool. [2] Gear arrangement according to claim 1 or according to the preamble of claim 1, characterized by that the toothing width of the first gear (7) directly adjoins the toothing width of the second gear (13). [3] Gear arrangement according to claim 1 or 2, characterized by that the second gear (13) is formed directly onto the intermediate shaft (1). [4] Gear arrangement according to claim 1 or 2, characterized by that the intermediate shaft (1) is designed as a hollow shaft. [5] A gear arrangement for transmitting the drive power of a motor vehicle, comprising an intermediate shaft (1) mounted on both sides by a roller bearing (2, 3) each, on which intermediate shaft (1) at least one first gear (7) and one second gear (13) are arranged to form a gear stage, wherein the first gear (7) has a larger diameter than the second gear (13) and can be releasably attached to the intermediate shaft (1) via a shaft-hub connection, wherein in the assembled state a first gear side surface (8) of the first gear (7) comes to rest against a stop shoulder (9) of the intermediate shaft (1), wherein to secure the releasable connection of the first gear (7) to the intermediate shaft (1) a washer-shaped lock nut (10) is provided, which can be screwed via an internal thread (16) onto an external thread (15) cooperating therewith and formed axially adjacent to the shaft-hub connection on the intermediate shaft (1) in such a way thatthat the locking nut (10) in the assembled state is completely received by a corresponding annular disc-shaped recess (11) in a second gear side surface (12) of the first gear (7), , characterized by that the intermediate shaft (1) is equipped at each end with conical raceway sections (5, 6) of a tapered roller bearing for rolling bearings on both sides, each tapering towards the shaft end, on which the rolling elements (4) roll. [6] Gear arrangement according to claim 5, characterized by that the one conical raceway section (5) is arranged directly axially adjacent to the external thread (15) of the intermediate shaft (1). [7] Gear arrangement according to claim 1, 2 or 5, characterized by that the stop shoulder (9) of the intermediate shaft (1) is formed by a flank side of the second gear (13). [8] Gear arrangement according to claim 1, 2 or 5, characterized bythat the shaft-hub connection between the first gear (7) and the intermediate shaft (1) is designed as a positive-locking spline or as a tongue-and-groove connection. [9] Gear arrangement according to claim 1, 2 or 5, characterized by that the shaft-hub connection between the first gear (7) and the intermediate shaft (1) is designed as a force-locking press connection. [10] Motor vehicle with a transmission arrangement for transmitting a drive power according to one of the preceding claims.

Images