ACTUATOR WITH HOLLOW WORM

Abstract

The invention relates to an actuator with an anti-backbend chain, a drive motor, and a worm which can be driven by the drive motor. The anti-backbend chain has alternating inner and outer chain links, and chain pins which connect the links, wherein at least some of the chain pins have laterally protruding engagement regions which engage with the worm in order to drive the anti-backbend chain. Such an actuator is to have a more advantageous design. For this purpose, the worm is designed as a hollow worm, and the engagement regions of the chain pins engage with an inner helical surface of the hollow worm.

Claims

1.-15. (canceled)

16. An actuator, comprising: a drive motor; a worm having a helical groove and driveable by the drive motor; and an anti-backbend chain including alternating inner and outer chain links and chain pins which connect the inner and outer chain links, at least some of the chain pins having engagement regions which project laterally and engage with the worm to drive the anti-backbend chain, wherein the worm is designed as a hollow worm, said engagement regions of the chain pins being in engagement with an internal helical surface of the hollow worm.

17. The actuator of claim 16, wherein the drive motor is arranged as an extension of the hollow worm.

18. The actuator of claim 16, wherein the drive motor defines a motor axis, said motor axis and a hollow worm axis being arranged coaxially to each other.

19. The actuator of claim 16, wherein the hollow worm is designed with multiple threads and resultant plural internal helical surfaces.

20. The actuator of claim 16, wherein the chain pins of the anti-backbend chain project alternately on one side and on another side of the anti-backbend chain, forming corresponding ones of the engagement regions.

21. The actuator of claim 20, wherein the engagement regions of the chain pins on one side of the anti-backbend chain engage in a different internal helical surface than the engagement regions of the chain pins on the other side of the anti-backbend chain.

22. The actuator of claim 16, further comprising a guide extending through the hollow worm and configured to guide a front side and/or a back side of the anti-backbend chain.

23. The actuator of claim 16, wherein the drive motor has a hollow shaft through which the anti-backbend chain is guided.

24. The actuator of claim 23, further comprising a guide extending through the hollow shaft of the drive motor and configured to guide a front side and/or a back side of the anti-backbend chain.

25. The actuator of claim 16, wherein the drive motor has a transmission and a transmission shaft which drives the hollow worm.

26. The actuator of claim 25, wherein the hollow worm includes an engagement region in which an engagement means driven by the transmission shaft engages to drive the hollow worm.

27. The actuator of claim 16, wherein the anti-backbend chain is deflected in a space between the hollow worm and the drive motor, and guided laterally out of the space.

28. The actuator of claim 27, wherein the anti-backbend chain has a section which is guided laterally out of the space and represents a non-loaded section of the anti-backbend chain.

29. The actuator of claim 16, wherein the anti-backbend chain is a bush chain or roller chain having a width which is greater than an inside diameter of the hollow worm, and less than an outside diameter of the internal helical surface of the hollow worm.

30. The actuator of claim 16, wherein the hollow worm is mounted by its outer circumference.

31. The actuator of claim 16, wherein a pushing direction of the anti-backbend chain points away from the drive motor in a direction of, or parallel to, the motor axis

Description

[0023] Clip-in magnetic markings (position elements) can be used as reference points, by means of which the electronic control unit may divide the total travel path into any number of partial paths. In the following, embodiments of the present invention will be explained in more detail with reference to drawings, wherein:

[0024] FIG. 1: shows a schematic illustration of a first embodiment of an actuator according to the invention,

[0025] FIG. 2: shows a cross-sectional view of an embodiment of a hollow worm,

[0026] FIG. 3: shows a perspective view of a guided anti-backbend chain and a hollow worm,

[0027] FIG. 4: shows a full section of the arrangement of FIG. 3, cut along the line IV.-IV.

[0028] FIG. 5: shows a front view of the arrangement of FIG. 3, and

[0029] FIG. 6: shows a schematic view of a second embodiment of an actuator according to the invention.

[0030] The actuator 1 shown schematically in FIG. 1 comprises, as essential components, an electric drive motor 2 with a transmission 3, a hollow worm 4 driven by the drive motor 2, and an anti-backbend chain 5. The transmission shaft 6 with a toothed wheel 7 arranged thereon in a torque-proof manner, which engages with an outer toothing 8 of the hollow shaft 4, is also included in the drawing. The anti-backbend chain 5 is deflected in the space 9 between the drive motor 2 and the hollow worm 4. The deflection can be guided or unguided. If the section of the anti-backbend chain 5 which is guided laterally out of the space 9 will apply the pushing force transverse to the motor axis A.sub.M, a guide for the anti-backbend chain 5 must be included which accordingly absorbs the pushing force. For most purposes, it can be contemplated that the pushing force is applied away from the drive motor 2 along the hollow worm axis A.sub.R, because then the deflection can take place in the space 9 substantially in the force-free section. The force-free section of the anti-backbend chain 5 can then be deflected further in a suitable manner to produce a chain depotfor example, along the drive motor 2 with the transmission 3.

[0031] The illustrated embodiment has the advantage that the outer toothing 8 results in a further reduction together with the toothed wheel 7, which is why the transmission 3 can have a simplified design. The motor shaft engages accordingly with the transmission 3, such that the transmission shaft 6 is driven.

[0032] The anti-backbend chain 5 is preferably a bush or roller chain which engages with the internal contour of the hollow worm and is moved by the same in the longitudinal direction.

[0033] An embodiment of a hollow worm 4 will now be explained in more detail with reference to FIG. 2. Such a hollow worm 4 can also be used in an embodiment according to FIG. 1. The hollow worm 4 has a cylindrical shoulder 10 on one end, which can either be used for the arrangement of a hardened toothed ring providing the outer toothing 8 (see FIG. 1) or for the arrangement of a bearing 11 (see FIG. 4, for example). The hollow worm 4 is designed with multiple threads, and has two internal helical surfaces 12.1 and 12.2 with the same slope. Each of the grooves which form the internal helical surfaces 12.1 or 12.2 is rectangular in cross-section. The internal helical surfaces 12.1, 12.2 are incorporated in the cylindrical opening 3 of the hollow worm 4. The internal helical surfaces 12.1 and 12.2 are in engagement with suitable engaging means of the anti-backbend chain 5. When the worm 4 turns, this leads to a longitudinal movement of the anti-backbend chain 5 guided through the cylindrical opening 13.

[0034] In the following, the interaction of the anti-backbend chain 5 with the hollow worm 4 will be explained in more detail with reference to an embodiment and to FIGS. 3-5.

[0035] The illustrated anti-backbend chain 5 is a roller chain with alternating inner chain links 14 and outer chain links 15. Each inner chain link 14 comprises, in a known manner, two mutually parallel inner plates which are interconnected by means of two mutually spaced sleeves. Rotatable rollers are arranged on the sleeves. Each outer chain link 15 comprises two mutually parallel outer plates which are connected to each other by means of two pivot pins 16.1 and 16.2. The pivot pins 16.1 and 16.2 are each inserted through the associated sleeves of the adjacent inner chain links 14 to form a chain link. Between the inner chain links 14 and the outer chain links 15, stiffening tabs are arranged. These allow a pivoting of the anti-backbend chain 5 in at least one direction, but also allow the transmission of a pushing force by means of the anti-backbend chain 5. The chain pins 16.1 and 16.2 have an extended construction, and project laterally on alternating, different sides, forming corresponding engagement regions 18.1 and 18.2. These come into engagement with the respective, internal helical surfaces 12.1 and 12.2 of the hollow worm 4. The total width B.sub.K of the anti-backbend chain 5 is greater than the inner diameter D.sub.I of the cylindrical opening 13, and slightly smaller than the outer diameter D.sub.W of the internal helical surfaces 12.1 and 12.2. The use of a multi-thread hollow worm 4 leads to a large feed movement of the anti-backbend chain 5 with an increased possibility of engagement provided by the engagement regions 18.1 and 18.2 of the chain pins 16.1 and 16.2. Every two chain pins 16.1 or 16.2 project on the same side of the anti-backbend chain 5 to form one of the engagement regions 18.1 and 18.2. In addition to the anti-backbend chain 5, a guide 19 which is composed of two guide rails 20.1 and 20.2 is also inserted through the hollow worm 4. The guide rails 20.1 and 20.2 are adapted, along their spines, to the circular shape of the cylindrical opening 13, such that they have a corresponding spacing from the same. On their inwardly facing surfaces, the guide rails 20.1, 20.2 are designed in such a manner that the rollers of the anti-backbend chain 5 roll along the same. The end faces of the guide rails 20.1 and 20.2 are bolted to corresponding attachment strips 21. The length of the guide 19 can be selected according to the concept of the actuator 1, Appropriately adapted guides can be used depending on whether the anti-backbend chain 5 is merely guided in a straight line orfor example, according to the embodiment in FIG. 1is deflected laterally.

[0036] In the following, the mode of action and operation of the actuator 1 according to the invention will be explained in more detail. The use of a rotating hollow worm 4 driven by the drive motor 2 leads to a substantially symmetrical force application into the anti-backbend chain 5, since the same engages on both sides thereof with the drive elementthe hollow worm 4. Axial forces are very efficiently directed into the anti-backbend chain 5 as a result. The various forms of drive by means of a drive motor 2 and an associated transmission 3 open up numerous possibilities for the construction, such that an adaptation to the different installation conditions is possible. To achieve the slimmest possible design of actuators 1, however, it is preferred that the hollow worm 4 and the drive motor 2 with the transmission 3 are arranged substantially one behind the other, as is the case in FIG. 1. There can also be a slight offset of the sleeve axis A.sub.H and the motor axis A.sub.M. In one embodiment according to FIG. 1, the pushing force can be applied by the drive motor 2 both in the longitudinal direction (that is, substantially parallel to the motor axis A.sub.M), and transverselypreferably perpendicular to the motor axis A.sub.M. This depends largely on the design of the anti-backbend chain 5 and the guidance. However, the pushing force is preferably applied substantially in extension and/or parallel to the motor axis A.sub.M, such that the load-free section of the anti-backbend chain 5 can also be deflected several times to accommodate the anti-backbend chain 5 in a chain depot (not shown).

[0037] In the following, a further embodiment of an actuator 1 according to the invention will be explained in more detail with reference to FIG. 6.

[0038] The essential difference in this embodiment is that the axis A.sub.H of the hollow worm 4 is substantially coaxial with the motor axis A.sub.M of the drive motor 2. For this purpose, the motor shaft of the drive motor 2 is designed as a hollow shaft. Also, the transmission 3 is designed in such a manner that the anti-backbend chain 5 can be guided centrally through the transmission 3. In this case, a central, hollow transmission shaft can be contemplated. The driving transmission shaft 6 is also designed as a hollow shaft, and is coupled to the hollow worm 4. In such an embodiment, it is not absolutely necessary to deflect the anti-backbend chain 5. An actuating length of anti-backbend chain 5 is essentially automatically available which substantially corresponds to the length of the drive motor 2 including the length of the transmission 3 with the transmission shaft 6. Nevertheless, a chain depot in which a deflection of the anti-backbend chain 5 can occur can also be behind the drive motor 2. Also in this embodiment, it is possible that the anti-backbend chain 5 transmits a pushing force in both directions. Preferably, however, the pushing force is applied away from the drive motor 2because the greatest actuation length is usually available in this direction (see pushing direction S in FIG. 6). A suitable guide 19 can then extend through the transmission 3 and the drive motor 2, as well as through the hollow worm 4.

[0039] The actuator 1 according to the invention is preferably driven electrically and can be a substitute for the concept of hydraulic- or pneumatic cylinders. For this reason, slim designs with a pushing force application in the longitudinal direction along the axis A.sub.H of the hollow worm 4 and the motor axis A.sub.M of the drive motor 2 are preferred. The drive motor 2, together with the transmission 3 and the hollow worm 4, can be accommodated in a shared housing, on the front end of which the actuating region of the anti-backbend chain 5 emerges. Also, a chain depot can be accommodated inside this housing, such that a structural unit results which is similar to a hydraulic cylinder or a pneumatic cylinder. The housing can be equipped on an end opposite the actuating region of the anti-backbend chain 5 with a corresponding attachment devicesuch as a joint head with ball joint. By means of the actuator 1 described here, pushing forces can be applied in the manner required for, by way of example, opening windows or doors, etc. Other applicationsfor example, in the context of conveying and transportare also possible.

LIST OF REFERENCE NUMBERS

[0040] 1 actuator [0041] 2 drive motor [0042] 3 transmission [0043] 4 hollow worm [0044] 5 anti-backbend chain [0045] 6 transmission shaft [0046] 7 toothed wheel [0047] 8 outer toothing [0048] 9 space [0049] 10 shoulder [0050] 11 bearing [0051] 12.1, 12.2 inner helical surfaces [0052] 13 cylindrical opening [0053] 14 inner chain link [0054] 15 outer chain link [0055] 16.1, 16.2 chain pins [0056] 17 stiffening plates [0057] 18.1, 18.2 engagement region [0058] 19 guide [0059] 20.1, 20.2 guide rail [0060] 21 attachment strip [0061] A.sub.H hollow worm axis [0062] M.sub.A motor axis [0063] D.sub.W internal: helical surface diameter [0064] D.sub.I internal opening diameter [0065] S pushing direction