DRIVE SHAFT FOR AN ELEVATOR SYSTEM

Abstract

A drive shaft for an elevator system, includes a support shaft and a traction sheave with at least one traction face for driving a traction mechanism, for example a drive belt, of the elevator system. A connection is provided for the transmission of a drive torque from the support shaft to the traction sheave, the traction sheave being of separate configuration from the support shaft. The traction sheave is held with an inner guide face on an outer guide face of the support shaft. The connection includes at least one axially projecting traction sheave-side circumferential stop which is in positively locking engagement with a support shaft-side circumferential stop.

Claims

1.-12. (canceled)

13. A drive shaft for an elevator system, comprising: a support shaft comprising an outer guide face, a traction sheave comprising an inner guide face and a traction face configured to drive a traction mechanism of the elevator system, and a connection configured to transmit a drive torque from the support shaft to the traction sheave, the traction sheave being of separate configuration from the support shaft, the traction sheave being held with the inner guide face thereof on the outer guide face of the support shaft, wherein the connection comprises an axially projecting traction sheave-side circumferential stop which is in positively locking engagement with a support shaft-side circumferential stop.

14. The drive shaft of claim 13 wherein the traction mechanism includes a drive belt.

15. The drive shaft of claim 13 wherein the traction sheave includes a centroid arranged concentrically with respect to a rotational axis thereof.

16. The drive shaft of claim 15 wherein the traction sheave comprises more than one traction sheave-side circumferential stop and every traction sheave-side circumferential stop is arranged with a common centroid on the rotational axis.

17. The drive shaft of claim 13 wherein the support shaft-side circumferential stop protrudes radially beyond the outer guide face.

18. The drive shaft of claim 13 wherein the traction sheave-side circumferential stop is arranged on an end side of the traction sheave.

19. The drive shaft of claim 13 wherein a second support shaft-side circumferential stop is arranged on a connecting piece which is of separate configuration from the support shaft.

20. The drive shaft of claim 13 wherein a first support shaft-side circumferential stop is arranged on a radial support shaft projection of the support shaft.

21. The drive shaft of claim 13 wherein the inner guide face has exclusively circular cross sections over its axial length, and/or the outer guide face has exclusively circular cross sections over its axial length.

22. The drive shaft of claim 13 wherein one or both of the inner guide face or the outer guide face is of cylindrical or conical configuration

23. The drive shaft of claim 13 wherein one or both of the inner guide face or the outer guide face is of completely cylindrical or completely conical configuration.

24. The drive shaft of claim 13 wherein the traction sheave-side circumferential stop is spaced apart from the drive axis, said spacing not less than 0.3 times or 0.5 times the diameter of the outer guide face of the support shaft, on which the traction sheave is guided axially in the region of the traction face.

25. An elevator system, comprising: a drive shaft, comprising: a support shaft comprising an outer guide face, a traction sheave comprising an inner guide face and a traction face configured to drive a traction mechanism of the elevator system, and a connection configured to transmit a drive torque from the support shaft to the traction sheave, the traction sheave being of separate configuration from the support shaft, the traction sheave being held with the inner guide face thereof on the outer guide face of the support shaft, wherein the connection comprises an axially projecting traction sheave-side circumferential stop which is in positively locking engagement with a support shaft-side circumferential stop.

26. The elevator system of claim 25, further comprising a support, the support having a radial support diameter, the traction face having a traction face diameter, a ratio of the traction face diameter and the radial support diameter being at most 40.

Description

[0031] The invention will be described in greater detail in the following text on the basis of the figures, in which:

[0032] FIG. 1 shows a drive shaft according to the invention in a perspective illustration,

[0033] FIG. 2 shows the drive shaft according to FIG. 1 in an exploded illustration,

[0034] FIG. 3 shows an elevator system according to the invention with a drive shaft according to FIG. 1, and

[0035] FIG. 4 shows two sections along the rotational axis through suitable supporting means and traction sheaves.

[0036] FIG. 3 shows an elevator system 5 according to the invention. The elevator system 5 comprises a car 6 which can be moved by means of a drive motor 7. The car 6 is held on a drive shaft 1 according to the invention by traction mechanisms in the form of drive belts 8. In said figure, four drive belts 8 are illustrated; the precise number of drive belts 8 is not important, however. The drive shaft 1 is connected to a drive motor 7. The drive shaft 1 will be described in greater detail on the basis of FIGS. 1 and 2. Belt drives of this type make the use of comparatively small traction sheaves possible, which in turn makes the use of comparatively small motors possible. Small shaft diameters of the drive shaft are therefore also required, however, which leads to high requirements with regard to their strength. This is because, in addition to the transmission of the drive torque, the drive shaft also has to support large parts, inter alia, of the weight of the car 6, the supporting means 8 and the counterweight (not shown).

[0037] FIGS. 1 and 2 will be described jointly in the following text. The drive shaft 1 according to the invention comprises a support shaft 2 which is connected to the drive motor via a connection which is described in greater detail. Two traction sheaves 3a, 3b are arranged on the support shaft 2, which traction sheaves 3a, 3b are separated spatially from one another by way of a bearing 9. The first traction sheave 3a is arranged on a first outer guide face 23a. A second traction sheave 3b is arranged on a second outer guide face. The first traction sheave 3a is arranged on a first outer guide face 23a. A second traction sheave 3b is arranged on a second outer guide face. In the present case, the traction sheaves 3a, 3b are of identical configuration with respect to one another, with the result that only the traction sheave 3 will be described in the further description.

[0038] The traction sheave 3 comprises three traction faces 32 which are separated from one another by way of circumferential webs 34. Precisely one drive belt 8 (FIG. 3) is guided on each traction face 32. The traction sheave 3 is of sleeve-like configuration; that means that a maximum radial wall thickness W of the traction face 32 is at most 0.5 times the axial extent L of a traction face 32. The wall thickness can be of considerably greater configuration in the region of the circumferential webs.

[0039] In order for it to be possible for both the support shaft 2 and the traction sheave 3 to be of as small and nevertheless as stable construction as possible, both the inner guide face 33 of the traction sheave and the outer guide face 23 of the support shaft 2 are of completely cylindrical configuration, in particular, in the highly loaded axial region of the traction faces 32. This means that the inner guide face has no deviation from the circular shape in all cross sections along the rotational axis A, which might otherwise bring about weakening of the strength.

[0040] In the case of known drive shafts of this type, the drive torque for an axial tongue and groove connection is formed radially between the guide faces, which brings about, however, the addressed weakening in the case of the support shaft and/or the traction sheave, depending on where a groove is provided.

[0041] According to the invention, provision is then mad for the torque to be introduced via in each case a traction sheave-side circumferential stop 43, which protrudes axially from an end side 31 of the traction sheave 3. Said traction sheave-side circumferential stop 43 is in engagement with a first or second support shaft-side circumferential stop 41, 42 which is driven by way of the support shaft.

[0042] Here, the invention provides two possible configurations. The first connection 4a of the first traction sheave 3a to the support shaft 2 comprises a radial support shaft projection 22. The corresponding first support shaft-side circumferential stop 41 is arranged on said support shaft projection 22. The support shaft projection 22 is connected fixedly to the support shaft 2 so as to rotate with it, and is configured, in particular, in one piece with the support shaft 2. In this case, the support shaft-side circumferential stop 41 is arranged in a groove. The traction sheave-side circumferential stop 43 is formed by way of an axial projection.

[0043] The second connection 4b of the second traction sheave 3b to the support shaft 2 has a connecting piece 40 which is fastened fixedly to an end side 21 of the support shaft 2 so as to rotate with it. Said connecting piece 40 protrudes beyond the end side 21 of the support shaft 2 in the radial direction. The second support shaft-side circumferential stop 42 is then arranged on said connecting piece 40. In this case, the support shaft-side circumferential stop 42 is also arranged in a connecting groove 44, and the traction sheave-side circumferential stop 43 is formed by way of the axial projection.

[0044] The connecting groove 44 also serves at the same time for connecting the connecting piece 40 to the support shaft 2 fixedly so as to rotate with it. For this purpose, the end side 21 of the support shaft 2 has a connecting tongue 24 which is of complementary configuration with respect to the connecting groove 44. For the fixed connection, the connecting piece 40 is screwed on the end side 21. To this end, the connecting piece 40 and the support shaft 2 in each case have fastening bores 45, 25 which are oriented with respect to one another on the end side 21.

[0045] The advantage then lies in the fact that a positively locking means in the form of a recess (for example, a groove) does not have to be provided either on the inner guide face 33 or on the outer guide face 23, which positively locking means might weaken the component. The support shaft and the traction sheave 3 can therefore be optimized completely for as low a weight as possible and as small a size as possible.

[0046] In the present exemplary embodiment, the guide faces 23, 33 are of cylindrical configuration. As an alternative, it is also possible that they are of conical configuration or are configured as a combination consisting of cylindrical and conical faces. Both the completely cylindrical shape and also the completely conical shape can be produced simply by way of turning, and always have a circular cross section along the rotational axis A.

[0047] In a self-explanatory manner, FIG. 4 illustrates the claimed ratio of T/d of the traction face diameter T and the radial supporting means diameter d, which ratio is at most 40.

LIST OF DESIGNATIONS

[0048] 1 Drive shaft [0049] 2 Support shaft [0050] 3 Traction sheave [0051] 4 Positively locking connection [0052] 5 Elevator system [0053] 6 Car [0054] 7 Drive motor [0055] 8 Supporting means [0056] 8a Drive cable [0057] 8b Drive belt [0058] 9 Bearing [0059] 21 End side of the support shaft [0060] 22 Radial support shaft projection [0061] 23 Outer guide face [0062] 24 Connecting tongue [0063] 25 Fastening bore [0064] 31 End side of the traction sheave [0065] 32 Traction face [0066] 33 Inner guide face [0067] 34 Circumferential web [0068] 40 Connecting piece [0069] 41 Support shaft-side circumferential stop on the support shaft projection [0070] 42 Support shaft-side circumferential stop on the connecting piece [0071] 43 Traction sheave-side circumferential stop [0072] 44 Connecting groove [0073] 45 Fastening bore [0074] A Rotational axis [0075] L Axial length of the traction face [0076] W Wall thickness of the traction sheave on the traction face [0077] D Diameter of the outer guide face [0078] T Diameter of the traction face [0079] d Radial diameter of the drive means