DE102008042159A1 - Worm gear and adjusting drive - Google Patents

Abstract

The invention relates to a worm gear (1), comprising a gear screw (3) whose working thread (7) cooperates with a worm toothing (6) of a driven gear (5) to transmit torque. According to the invention, a blocking element (10) is provided on the output gear (5), which can be converted into a blocking position (14) formed by a rotary movement of the output gear (5) into a blocking position (14) on the gear worm (3) in which there is a further rotational movement the output gear (5) blocking cooperating with the worm gear (3). Furthermore, the invention relates to an adjustment.

Description

State of the art

The The invention relates to a worm gear according to the The preamble of claim 1 and an adjusting drive for adjusting a motor vehicle component according to claim 10.

worm gear with acceptable efficiencies are insufficient self-locking. Therefore, in known Scheibenwischerverstellantrieben a self-locking over realized an extended position of a motor crank with wiper linkage.

From the WO 2004/113768 A1 It is known to provide a worm gear with a self-locking device that prevents or releases a movement of the transmission. For driving the worm gear, an electric motor is provided, wherein the self-locking device can be actuated with a separate actuator from the electric motor.

Disclosure of the invention

Technical task

Of the Invention is based on the object, an alternative worm gear to propose that, without having to provide a separate actuator, can be blocked in at least one direction of movement. It also exists the task is an adjustment for adjusting a Kraftfahrzeugkom component to provide with a correspondingly improved worm gear.

Technical solution

These Task is with respect to the worm gear with the features of claim 1 and with respect to the adjusting drive with the features of claim 10. Advantageous developments of Invention are specified in the subclaims. In the Within the scope of the invention, all combinations are omitted at least two of in the description, the claims and / or features disclosed in the figures.

Of the Invention is based on the idea at the output gear at least to provide a blocking element, which is not by a specially intended actuator, but by a rotary motion the output gear can be converted into a blocking position formed on the gear worm, in which it interacts with the worm gear in such a way that a further rotational movement of the output gear and thus also the gear worm prevented becomes. A trained according to the concept of the invention worm gear is characterized by a very simple and thus robust construction and is thus preferred for the Use in adjusting drives, especially in windscreen wiper drives or in power window drives, etc. suitable in motor vehicles. It is particularly advantageous that the worm gear without further external measures, such as active relative to the output gear adjustable blocking elements, gets by. The waiver of external Measures for implementing a self-locking with a Blocking or parking position not only leads to a simpler and more robust construction, but goes beyond also to a cost and weight reduction. It is preferred if the worm gear is assigned a reversible motor, which most preferably between a lower and an upper Wendelange with a reversing angle range of less than 360 °, wherein the blocking position (parking position / end position) is preferred is smaller than the lower turning position or larger is, as the upper turning position.

In Development of the invention is provided with advantage that the Blocking element rotatably connected to the output gear, either by a one-piece design with the output gear or through Setting the, preferably bolt-shaped, blocking element on the driven wheel. Preferably, the blocking element is such trained and arranged that it is the worm gearing in the radial Direction, preferably towards the gear screw, surmounted, to interact with this for the realization of the blocking function to be able to.

All it is particularly preferred if the blocking element is not within the worm gear, but adjacent to this, preferably immediately adjacent thereto in the circumferential direction, is arranged.

in the Regard to the way of realization of the blockage or the manner of interaction between the blocking element and the worm gear there are different ways. According to a first alternative, the blocking element acts from a defined rotational position positively with the Gear worm together, such that a further rotational movement of the Gear worm and the output gear is prevented. additionally or alternatively, according to a second alternative also a frictional interaction between blocking element and gear worm be realized.

According to a particularly advantageous embodiment of the worm gear this is designed or acts in such a way with a, in particular designed as a reversible motor, electric drive motor together that the maximum feasible rotation angle of the driven wheel is limited to below 360 °. The distance of the helical positions of the worm gear is thus also less than 360 °, wherein the blocking position is preferably realized in a region outside of the helical layers, so that the output gear can be adjusted freely between the helical positions and only for blocking purposes beyond this must be rotated.

In Development of the invention is advantageously provided that the worm gearing of the driven gear exclusively via a peripheral portion of the driven gear, so not complete is formed circumferentially, wherein it is further preferred that the Worm toothing is arranged such that they are compared to an angular position between the turns of the output gear when the blocking element is in the blocking position, no more or only with a reduced number of teeth with the Working thread of the screw is engaged.

All it is particularly preferred if for the transfer of the blocking element in its formed on the worm gear Blocking position in addition to the working thread a the Blocking element associated blocking thread is pre-see which most preferably only with the blocking element in engagement comes when the output gear in an area outside the upper and lower Wendelage moves, so a blockage the worm gear is desired. Very particularly preferred the output gear in the blocking position is exclusively over the blocking element with the worm gear or the blocking thread connected to the transmission worm torque transmitting and not in addition to the worm gearing.

Around an interaction of the blocking element with the worm gear is before reaching the blocking position, is in development of the invention advantageously provided that the diameter of the locking thread, in a direction away from the working thread considered, increases. In other words, the diameter of the Locking thread with increasing distance to the working thread, preferably, at least approximately, conical to.

In Development of the invention is provided with advantage that the Blocking position in the end of a thread groove of the blocking element is realized, through which the blocking element in the direction of the blocking position is adjusted during its rotation. In terms of training There are different possibilities for the blocking position. For example, the blocking position can be designed in such a way that the thread groove ends at the blocking position and the blocking element runs against a stop formed by the screw and / or the pitch of the thread groove can be in the area of the blocking position reduced, preferably reduced to zero, to be that way to prevent further propulsion. The movement of the blocking element out of the blocking position may preferably exclusively achieved by reversing the direction of rotation of the worm gear become.

The Invention also leads to an adjustment for adjusting a motor vehicle component, wherein the adjusting drive in addition to the previously explained worm gear preferably a reversible motor for driving the gear worm in two opposite directions Having circumferential directions. The adjusting drive may be, for example to act a windshield wiper drive or a window drive. The reversing motor preferably acts in such a way with the worm gear together that before reaching the blocking position, a reversal of direction the rotational movement of the worm gear takes place, and that only the worm gear over a turning point of the driven gear is moved out further, if a blockage of the worm gear and thus the entire adjustment is desired.

Brief description of the drawings

Further Advantages, features and details of the invention will become apparent the following description of preferred embodiments as well as from the drawings.

These show in:

1 to 4 a worm gear in different circumferential positions of the output gear,

5 : an enlarged detail 4 and

6 an alternative embodiment of a blocking position without thread pitch.

embodiments the invention

In The figures are the same elements and elements with the same Function marked with the same reference numerals.

In 1 is a worm gear 1 comprising one about an axis of rotation 2 rotatable, preferably by a reversible motor (not shown) driven, gear worm 3 and one to one perpendicular to the axis of rotation 2 extending axis of rotation 4 rotatable output gear 5 , shown. The driven wheel 5 comprises a snow arranged on the outer circumference ckenverzahnung 6 , which engage in a torque-transmitting engagement with a corresponding working thread 7 the worm gear 3 located. Depending on the direction of rotation of the worm gear 3 becomes the driven wheel 5 in one or the other circumferential direction about the axis of rotation 4 twisted.

As it turned out 1 results, the worm teeth extends 6 not over the full circumference of the output gear 5 but only over a peripheral portion. By rotation of the worm gear 3 is the output gear 5 between schematically indicated turning positions 8th . 9 rotatable. At a distance in the circumferential direction to a lower in the plane of the drawing Wendelage 9 the driven wheel 5 there is a blocking element 10 that the worm gearing 6 projected in the radial direction to the outside, wherein the blocking element 10 rotatably with the output gear 5 connected is. As long as the output gear 5 exclusively between the turns 8th . 9 is twisted back and forth comes the blocking element 10 no function too. Will the upper turning position 8th by further turning the worm gear 3 exceeded, the blocking element comes 10 in a torque-transmitting engagement with a locking thread 11 the worm gear 3 , which is next to the working thread 7 arranged and just like the working thread 7 non-rotatable with a shaft 12 connected is. As can be seen from the figures, the diameter of the blocking thread decreases 11 , starting from the left, to the working thread 7 adjacent end, in the direction of the drawing plane to the right, wherein the envelope of the locking thread 11 has a concave in cross-section curved conical shape.

How to get out 1 results, runs a thread groove 13 of the locking thread 11 towards a blocking position 14 adjacent to the working thread 7 , When the output gear 5 twisted counterclockwise so far that it is at the blocking position 14 arrives, it acts in the blocking position 14 blocking with the gear worm 3 together and thus prevents further rotation of the output gear 5 in the direction of the arrow 15 , From the blocking position 14 can the blocking element 10 only be moved out by the output gear 5 in one of the arrow directions 15 opposite circumferential direction by a corresponding control of the worm gear 3 is twisted.

In 2 is an operating condition of the worm gear 1 shown at the upper turning position 8th was exceeded, ie the worm gear 3 was twisted so far that the blocking element 10 in engagement with the thread groove 13 of the locking thread 11 comes. In a further twisting movement wanders the blocking element 10 , as out 3 results, further relative to the worm gear 3 towards the blocking position 14 , where in 4 a state shortly before reaching the blocking position 14 is shown.

Out 5 is the blocking position 14 out 4 shown in an enlarged view. It can be seen that the blocking position 14 is designed as a bayonet-like notch, which is the thread groove 13 engages behind. Get the blocking element 10 in the blocking position 14 , Is by positive engagement between the blocking element 10 and the worm gear 3 further rotation of the worm gear 3 and thus the output gear 5 safely prevented.

6 shows an alternative embodiment of the blocking position 14 , In the embodiment shown, the thread groove 13 in the blocking position 14 the slope is zero.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 2004/113768 A1 [0003]

Claims (10)

Worm gear, comprising a gear worm ( 3 ) whose working thread ( 7 ) with a Scheckenverzahnung ( 6 ) of a driven wheel ( 5 ) cooperating torque-transmitting, characterized in that on the output gear ( 5 ) a blocking element ( 10 ) is provided, which by a rotational movement of the driven wheel ( 5 ) in one of the gear worm ( 3 ) trained blocking position ( 14 ) is convertible, in which it, a further rotational movement of the driven wheel ( 5 ), with the worm gear ( 3 ) cooperates. Worm gear according to claim 1, characterized in that the blocking element ( 10 ) as integral with the output gear ( 5 ) formed or fixed to this, the worm gearing ( 6 ) is formed in the radial direction superior projection. Worm gear according to one of claims 1 or 2, characterized in that the blocking element ( 10 ) adjacent to the worm toothing ( 6 ) is arranged. Worm gear according to one of the preceding claims, characterized in that the blocking position ( 14 ) is formed such that the blocking element ( 10 ) in this frictionally and / or positively with the gear peck ( 3 ) cooperates. Worm gear according to one of the preceding claims, characterized in that the maximum rotational angle of the output gear ( 5 ) is limited to below 360 °. Worm gear according to one of the preceding claims, characterized in that the worm toothing ( 6 ) exclusively over a peripheral portion of the driven wheel ( 5 ). Worm gear according to one of the preceding claims, characterized in that the gear worm ( 3 ), preferably immediately adjacent to the working thread ( 7 ), the blocking element ( 10 ) associated blocking thread ( 11 ) for transferring the blocking element ( 10 ) into the blocking position ( 14 ) having. Worm gear according to one of the preceding claims, characterized in that the diameter of the blocking thread ( 11 ) with increasing distance to the working thread ( 7 ), preferably conical, increases. Worm gear according to one of claims 7 or 8, characterized in that the blocking position ( 14 ) in the end region of a thread groove ( 13 ) of the blocking thread ( 11 ), preferably as a bayonet catch-like impression or as a threaded portion with a pitch smaller than the pitch of the thread groove ( 13 ), preferably without pitch. Adjusting drive for adjusting a motor vehicle component, in particular windscreen wiper drive or window lift drive, comprising at least one electric motor, preferably by means of a reversible motor, driven worm gear ( 1 ) according to any one of the preceding claims.