SHAFT-HUB CONNECTION OF A DOUBLE GEAR ON A TRANSMISSION SHAFT

Abstract

A shaft-hub connection of a double gearwheel (2) on a transmission shaft (5), in which the double gearwheel (2) has a first gearwheel (3) and a second gearwheel (4), which are connected to one another in a rotationally fixed manner. The shaft-hub connection is in the form of a shrink fit (7) between a hub (8) of the first gearwheel (3) and the transmission shaft (5). A maximum of the torque to be transmitted can be transmitted by virtue of the shrink fit (7).

Claims

1-7. (canceled)

8. A shaft-hub connection of a double gearwheel (2) on a transmission shaft (5), the double gearwheel (2) comprising: a first gearwheel (3) and a second gearwheel (4) being connected to one another in a rotationally fixed manner, the shaft-hub connection being in a form of a shrink fit (7) between a hub (8) of the first gearwheel (3) and the transmission shaft (5), and a maximum torque to be transmitted being transmittable by virtue of the shrink fit (7).

9. The shaft-hub connection according to claim 8, wherein the first gearwheel and the second gearwheel (3, 4) are connected to one another by one of a positive locking, by a friction-force locking or in a material-merged manner.

10. The shaft-hub connection according to claim 8, wherein a hub (9) of the second gearwheel (4) is arranged, in an axial direction, adjacent the hub (8) of the first gearwheel (3).

11. The shaft-hub connection according to claim 10, wherein ends of the hub (8) of the first gearwheel (3) and the hub (9) of the second gearwheel (4), facing toward one another, are welded to one another,

12. The shaft-hub connection according to claim 8, wherein in an area of the shrink fit (7), a positive-locking element (10) is provided in order to prevent micro-displacement,

13. The shaft-hub connection according to claim 12, wherein the positive-locking element (10) is in a form of a dowel pin.

14. A transmission shaft arrangement with at least a first gearwheel and a second gearwheel, the first gearwheel (3) and the second gearwheel (4) being fixed on the transmission shaft (5) by a shaft-hub connection, the first gearwheel (3) and the second gearwheel (4) being connected to one another in a rotationally fixed manner, and the shaft-hub connection being in a form of a shrink fit (7) between a hub (8) of the first gearwheel (3) and the transmission shaft (5), and a maximum torque to be transmitted being transmittable by virtue of the shrink fit (7).

15. A gearwheel-transmission shaft arrangement, the arrangement comprising: a double gearwheel having first and second gearwheels being connected to a transmission shaft, the first gearwheel having a hub comprising an axial first end surface that is connected to the second gearwheel in a rotationally fixed manner by at least a materially-bonded connection, and the hub of the first gearwheel being connected, via a shrink-fit connection, to the transmission shaft such that a maximum amount of torque that is transmittable by a combination of the first and the second gearwheels, being transmitted between the transmission shaft and the first and the second gearwheels via the shrink-fit connection.

16. The arrangement according to claim 15, wherein the hub of the first gearwheel has an axial extension that extends axially from the first end surface, and the axial extension of the hub of the first gearwheel is received within a hub of the second gearwheel, and the hub of the second gearwheel is connected to the axial extension of the hub of the first gearwheel by either a shrink fit or a pres fit, and the first end surface of the hub of the first gearwheel is connected to the hub of the second gearwheel by a welded connection.

17. The arrangement according to claim 15, wherein the hub of the first gearwheel comprises a through bore and the transmission shaft comprises a blind bore and a positive-locking element extends from the through bore of the first gearwheel into the blind bore of the transmission shaft to prevent relative rotational micro-displacement between the hub of the first gearwheel and the transmission shaft

18. The arrangement according to claim 17, wherein the positive-locking element is a dowel pin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Below, the invention is explained in more detail with reference to the example embodiment illustrated in the figures, which show:

[0029] FIG. 1: A transmission shaft arrangement with a shaft-hub connection according to the invention, and

[0030] FIG. 2: An enlarged section of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] FIG. 1 shows the end area of a transmission shaft 5, which can rotate about a rotational axis 6. For this, the transmission shaft 5 can be mounted in a transmission housing (not shown), among other things by means of a roller bearing 13.

[0032] A double gearwheel 2 is fixed onto the transmission shaft 5 by means of a shaft-hub connection. The double gearwheel 2 consists of a first gearwheel 3 and a second gearwheel 4, which are joined to one another in a rotationally fixed manner. The first gearwheel 3 and the second gearwheel 4 are arranged next to one another in the axial direction, so that a hub 9 of the second gearwheel 4 is axially next to the hub 8 of the first gearwheel 3.

[0033] The rotationally fixed connection between the first gearwheel 3 and the second gearwheel 4 is produced in this example embodiment by welding the two gearwheels 3 and 4 to one another. For this purpose, the end faces of the hub 8 of the first gearwheel 4 and of the hub 9 of the second gearwheel 4 facing toward one another are welded together.

[0034] The shaft-hub connection is formed as a shrink fit 7 between the hub 8 of the first gearwheel 3 and the transmission shaft 5. The shrink fit 7 is designed in such a way that a maximum torque to be transmitted can be transmitted by way of the shrink fit 7. To ensure a required shrink fit security and torque transmission ability of the shrink fit, in advance suitable parameters such as shrink fit length and oversize at the shrink fit site are calculated and determined. For this, in addition to the torque load data, additional loads such as axial loads that occur during operation are taken into account. Furthermore, for this purpose a knowledgeable person will have chosen suitable materials for the gearwheels and the transmission shaft, as well as surface properties at the shrink fit surfaces of the gearwheel hub and the transmission shaft.

[0035] To prevent micro-displacements a dowel pin 10 is provided in the area of the shrink fit 7. The dowel pin extends from a through-going bore 11 in the hub 8 of the first gearwheel 3 into a blind bore 12 in the transmission shaft 5, and in that way secures the position of the double gearwheel 2 on the transmission shaft 5, even during load peaks in long-term operation, without transmitting any torque during normal operation.

[0036] FIG. 1 also shows partial views of a third gearwheel 14 and a fourth gearwheel 15, which are arranged to rotate about a further rotational axis 20. The further rotation axis is associated for example with a main transmission shaft (not shown) and extends parallel to the rotation axis 6 of the transmission shaft 5. In this example embodiment the transmission shaft 5 is a countershaft to the main transmission shaft. The first gearwheel 3 of the countershaft meshes with the third gearwheel 14 of the main transmission shaft and the second gearwheel 4 of the countershaft meshes with the fourth gearwheel 15.

[0037] Between the gearwheels 14 and 15 on the main transmission shaft, which are loose wheels, is arranged a shifting unit 16 by means of which the power flow can be directed optionally by way of the first gearwheel 3 and the third gearwheel 14 or by way of the second gearwheel 4 and the fourth gearwheel 15 on the main transmission shaft. The shifting unit 16 is arranged in an intermediate space between the gearwheels 3, 4, 14 and 15, so that the fitting space available is used in an optimum manner.

[0038] FIG. 2 shows an enlarged section of FIG. 1, in which, in particular, the fixing of the second gearwheel 4 over the first gearwheel 3 on the transmission shaft 5 can be seen more clearly.

[0039] At its end facing toward the first gearwheel 3, the hub 9 of the second gearwheel 4 is welded to the hub 8 of the first gearwheel 3. In addition to the weld seam 17 which joins the two hubs 8 and 9 to one another in a material-merged way, a further shrink or press fit 18 is formed between the two gearwheels 3 and 4. This further shrink or press fit 18 serves in particular to ensure the precise positioning of the two gearwheels 3 and 4 relative to one another, and to further strengthen the connections between the two gearwheels 3 and 4.

[0040] In FIG. 2 it can be seen clearly that there is no contact between the second gearwheel 4 and the transmission shaft 5. Instead, between the inside circumferential surface of the hub 9 of the second gearwheel 4 and the outer circumferential surface of the transmission shaft 5 there is an air gap 19.

INDEXES

[0041] 1 Transmission shaft arrangement
2 Double gearwheel
3 First gearwheel
4 Second gearwheel
5 Transmission shaft
6 Rotational axis

7 Shrink fit

8 Hub

9 Hub

10 Dowel pin

11 Bore

[0042] 12 Blind bore
13 Roller bearing
14 Third gearwheel
15 Fourth gearwheel
16 Shifting unit
17 Weld seam
18 Further shrink fit

19 Air gap

[0043] 20 Further rotational axis