METHOD FOR INSTALLING A WRAP SPRING

Abstract

A method for installing a wrap spring includes providing a first sleeve with a first longitudinal axis extending in an axial direction and a lateral surface, and the wrap spring designed to frictionally abut the lateral surface. The wrap spring includes a nominal diameter and a central axis. The method includes applying the wrap spring in a relaxed state to the lateral surface at an angle α between the central axis and the first longitudinal axis, elastically twisting the wrap spring to change the nominal diameter while the wrap spring contacts the lateral surface, reducing the angle α, threading the wrap spring onto the first sleeve, and relaxing the wrap spring to establish frictional contact with the lateral surface.

Claims

1.-10. (canceled)

11. A method for installing a wrap spring, comprising providing a first sleeve comprising: a first longitudinal axis extending in an axial direction; and a lateral surface; providing the wrap spring designed to frictionally abut the lateral surface, the wrap spring comprising: a nominal diameter; and a central axis; applying the wrap spring in a relaxed state to the lateral surface at an angle α between the central axis and the first longitudinal axis; elastically twisting the wrap spring to change the nominal diameter while the wrap spring contacts the lateral surface; reducing the angle α; threading the wrap spring onto the first sleeve; and relaxing the wrap spring to establish frictional contact with the lateral surface.

12. The method of claim 11 wherein the threading the wrap spring onto the first sleeve comprises: inserting the wrap spring into the first sleeve; or slipping the wrap spring onto the first sleeve.

13. The method of claim 11 wherein the elastically twisting the wrap spring and the threading the wrap spring take place at least temporarily at the same time.

14. The method of claim 11 wherein the reducing the angle α and the threading the wrap spring take place at least temporarily at the same time.

15. The method of claim 11 wherein, after the threading the wrap spring the wrap spring protrudes partially from the first sleeve in the axial direction.

16. The method of claim 11 wherein: the first sleeve comprises a first axial stop; and the threading the wrap spring comprises the wrap spring axially striking the first axial stop.

17. The method of claim 11 wherein: the wrap spring comprises a plurality of coils; and only some of the plurality of coils slide at the angle α on the later surface during the threading the wrap spring.

18. The method of claim 17 wherein the only some of the plurality of coils is exactly six to eight coils.

19. The method of claim 11 further comprising providing a robot arm, wherein the applying the wrap spring, the elastically twisting the wrap spring and the threading the wrap spring is aided by the robot arm.

20. The method of claim 11 further comprising: providing a second sleeve arranged to frictionally contact the wrap spring in the relaxed state, the second sleeve comprising a second longitudinal axis; applying the second sleeve to the wrap spring at an angle β between the second longitudinal axis and the central axis after the threading the wrap spring and before the relaxing the wrap spring; and threading the second sleeve onto the wrap spring.

21. The method of claim 20 wherein the threading the second sleeve comprises: pushing the second sleeve onto the first sleeve; or inserting the second sleeve into the first sleeve.

22. The method of claim 20 wherein the second longitudinal axis wobbles during the threading the second sleeve.

23. The method of claim 20 wherein the relaxing the wrap spring is after the threading the second sleeve.

24. The method of claim 20 further comprising providing a robot arm, wherein the applying the wrap spring, the elastically twisting the wrap spring, the threading the wrap spring, the applying the second sleeve and the threading the second sleeve is aided by the robot arm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the following, the disclosure is explained by way of example with reference to the accompanying drawings using exemplary embodiments, in which the features shown below can represent an aspect of the disclosure both individually and in combination. In the figures:

[0018] FIG. 1 shows a schematic sectional view of a wrap spring clutch at a first installation time point,

[0019] FIG. 2 shows a schematic sectional view of the wrap spring clutch at a second installation time point,

[0020] FIG. 3 shows a schematic sectional view of the wrap spring clutch at a third installation time point,

[0021] FIG. 4 shows a schematic sectional view of the wrap spring clutch at a fourth installation time point,

[0022] FIG. 5 shows a schematic sectional view of the wrap spring clutch at a fifth installation time point,

[0023] FIG. 6 shows a schematic sectional view of the wrap spring clutch at a sixth installation time point,

[0024] FIG. 7 shows a schematic sectional view of the wrap spring clutch at a seventh installation time point, and

[0025] FIG. 8 shows a schematic sectional view of the wrap spring clutch at an eighth installation time point.

DETAILED DESCRIPTION

[0026] To install the wrap spring clutch 10 partially shown in FIG. 1, a first sleeve 12 is initially provided, into which a wrap spring 14 is to be inserted. For this purpose, a robot arm gripping the wrap spring 14 can apply the wrap spring 14 at an angle to the first sleeve 12 by providing an angle α between a central axis 16 of the wrap spring 14 and a first longitudinal axis 18 of the first sleeve. The wrap spring 14 can be elastically twisted in the winding direction before it is applied to the first sleeve 12, while it is applied to the first sleeve 12 or after it is applied to the first sleeve 12, so that the outer diameter of the wrap spring 14 is reduced. In the elastically twisted state of the wrap spring 14, the external diameter of the wrap spring 14 is smaller than an internal diameter of an internal lateral surface 20 of the first sleeve 12.

[0027] The wrap spring 14 can be threaded onto the first sleeve 12 by inserting the wrap spring 14 into the first sleeve 12, as shown in FIG. 2. Here, a few coils of the wrap spring 14 at an angle can slide off the edge of the lateral surface 20. In addition, the angle α between the central axis 16 of the wrap spring 14 and the first longitudinal axis 18 can be reduced until the angle α is 0° and the wrap spring 14 is completely set up to be coaxial with the first sleeve 12, as shown in FIG. 3. If the wrap spring 14 has not yet reached the designated axial position thereof relative to the first sleeve 12, the wrap spring 14 can be inserted further into the first sleeve 12 via an axial relative movement until the wrap spring 14 strikes a first axial stop 22 of the first sleeve 12, as shown in FIG. 4. In this case, the wrap spring 14 can protrude somewhat in the axial direction from the first sleeve 12.

[0028] As shown in FIG. 5, a second sleeve 24 can be applied at an angle to the protruding part of the wrap spring 14. A second longitudinal axis 26 can be set at an angle β to the central axis 16 of the wrap spring 14 and at an angle to the first longitudinal axis 18. The second sleeve 24 can slide on the first sleeve 12 and/or on the wrap spring 14 in the axial direction, as shown in FIG. 6. Here, the second sleeve 24 can stand up and be arranged to be coaxial to the wrap spring 14, as shown in FIG. 7. In the exemplary embodiment shown, both the first sleeve 12 and the second sleeve 24 are arranged radially outside of the wrap spring 14. When the second sleeve 24 is completely threaded, as shown in FIG. 8, the first sleeve 12 and the second sleeve 24 can be connected to one another and form a common, radially inwardly facing lateral surface 20 on which the wrap spring 14 in the finally relaxed state can produce a frictional engagement.

[0029] A further sleeve or shaft can be inserted radially within the wrap spring 14, with which the wrap spring 14 can be connected in a fixed manner to one end of the windings, for example to form the complete wrap spring clutch 10 within a belt pulley for driving ancillary units of a motor vehicle.

REFERENCE NUMERALS

[0030] 10 Wrap spring clutch [0031] 12 First sleeve [0032] 14 Wrap spring [0033] 16 Central axis [0034] 18 First longitudinal axis [0035] 20 Lateral surface [0036] 22 First axial stop [0037] 24 Second sleeve [0038] 26 Second longitudinal axis [0039] α Angle [0040] β Angle