DE102015211099A1 - Actuator arrangement with a planetary gear - Google Patents

Abstract

The invention relates to an actuator arrangement, comprising an actuator (1), a planetary gear (2) and a mechanism (3) to be actuated by the actuator (1). The planetary gear (2) has a variable, periodically changing translation and is at least indirectly connected to the actuator (1), wherein the planetary gear (2) a first planetary gear set (4) with respective round rolling circles (4a, 4b), and a second planetary gear set (5) with respective non-circular rolling circles (5a, 5b). A coincidence of the rolling circles (4a, 4b, 5a, 5b) of the first and second planetary gear sets (4, 5) causes an automatic standstill of the planetary gear (2), whereby a stepwise adjusting movement of the actuator assembly in each case until the agreement of the rolling circles (4a, 4b, 5a, 5b) of the first and second planetary gear set (4, 5) is realized.

Description

The invention relates to an actuator assembly comprising an actuator, a planetary gear and a mechanism to be actuated by the actuator. The planetary gear has a variable, periodically changing gear ratio and is at least indirectly connected to the actuator, wherein the planetary gear has a first planetary gear set with respective circular pitch circles, and a second planetary gear set with respective non-circular pitch circles.

Field of the invention

Planetary gears with round and non-circular planetary gear sets are state of the art. So goes for example from the US 4,788,891 A1 a planetary gear forth, which has a first planetary gear set with respective round rolling circles, and a second planetary gear set with respective non-circular rolling circles. In this case, the first planetary gear meshes with a first sun, which also has a circular pitch circle, wherein the second planetary gear meshes with a second sun, which has a non-circular pitch circle.

In the design of gearboxes for actuators, there is a conflict of objectives to overcome, because the translation and the efficiency of the transmission should be as high as possible. Furthermore, it is advantageous to form the gear self-locking, to dispense with a necessary standstill of the transmission to a holding torque and an associated holding current. Both poor efficiencies and a holding current at a necessary standstill lead to unnecessary energy losses, which must be avoided.

task

Therefore, the object of the invention is to provide an actuator assembly which does not have the aforementioned disadvantages and thus has both a high gear ratio and a high efficiency.

Inventive solution

According to the invention causes a coincidence of the rolling circles of the first and second planetary gear set an automatic standstill of the planetary gear, whereby a stepwise adjusting movement of the actuator assembly is realized in each case to match the pitch circles of the first and second planetary gear set.

In other words, the two planetary gear sets are designed and arranged such that a zero pass provides a coincidence of the pitch circles of the first and second planetary gear set. When setting the zero crossing, the sum of the applied forces is zero, whereby a stop of the planetary gear is generated. Thus, the step-by-step positioning movement between the zero passes is thereby realized. The planetary gear thus requires neither a self-locking training nor the introduction of a holding torque for fixing a required position. As a result, the planetary gear has both a high gear ratio and high efficiency.

Preferably, the planetary gear is designed as a plus gear. Thus, the stand translation is positive. In a first position of the planetary gear, which is provided before or after a zero pass, the translation is not equal to +1. During the first position the translation changes continuously. In contrast, in a second position of the planetary gear, namely in the zero pass, the translation +1, and thus is maximum.

The invention includes the technical teaching that the first planetary gear set is rotatably formed with the second planetary gear set. The two planetary gear sets are pressed together, in particular via a positive connection, welded or formed as a stepped planetary gear set.

Particularly preferably, the two planetary gear sets are rotatably mounted on a common planet carrier. Furthermore, the common planet carrier is preferably connected at least indirectly to the actuator. In particular, the common planet carrier via a drive shaft which feeds torque from the actuator in the planetary gear, connected to the actuator.

Preferably, the first planetary gearset meshes with a first sun and the second planetary gearset with a second sun. In this case, the first sun as well as the first planetary gear set on a round pitch circle, the second sun as well as the second planetary gear has a non-circular pitch circle. Out-of-round is to be understood as both oval and polygonal.

Further preferably, one of the two suns is stationary and the other of the two suns is connected to an output shaft. Thus, either the first sun can be fixed stationary, in which case the second sun is connected to the output shaft, or the second sun can be stationary, in which case the first sun is connected to the output shaft.

According to a preferred embodiment, the actuatable by the actuator Mechanism a level control for a motor vehicle. Furthermore, according to a further preferred embodiment, it is also conceivable that the mechanism to be actuated by the actuator is a seat adjustment for a motor vehicle.

Brief description of the drawing

Further measures improving the invention will be described in more detail below together with the description of preferred embodiments of the invention with reference to FIGS. Show it

1 2 is a simplified schematic illustration for illustrating the structure of an actuator arrangement according to the invention with an actuator, a planetary gear and a mechanism to be actuated by the actuator,

2 a simplified schematic illustration illustrating a plurality of rolling circles of gears of the planetary gear according to a first position, and

3 a simplified schematic representation illustrating a plurality of rolling circles of gears of the planetary gear according to a second position.

Detailed description of the drawing

According to 1 an actuator assembly according to the invention comprises an actuator 1 , a planetary gear 2 and one from the actuator 1 mechanism to be operated 3 on. The planetary gear 2 is via a drive shaft 10 with the actuator 1 and an output shaft 9 with the mechanism 3 connected. The from the actuator 1 mechanism to be operated 3 may be a level control or a seat adjustment for a motor vehicle.

The planetary gear 2 has a variable, periodically varying translation and includes first and second planetary gear sets 4 . 5 , Furthermore, the planetary gear comprises 2 a planet carrier 6 on which the two planetary gear sets 4 . 5 are rotatably mounted. The first planetary gear set 4 is rotatably with the second planetary gear set 5 educated. Furthermore, the common planet carrier 6 over the drive shaft 10 with the actuator 1 connected. The first planetary gear set 4 combs with a first sun 7 , where the second planetary gear set 5 with a second sun 8th combs. This is the first sun 7 with the output shaft 9 connected and the second sun 8th fixed in place. The planetary gear 2 is designed as a plus gear.

According to 2 is a first position of the respective planetary gear set 4 . 5 at the respective sun 7 . 8th shown. In this first position, the ratio of the planetary gear is not +1. The respective planetary gear sets 4 . 5 revolve upon actuation of the - not shown - mechanism 3 by the - not shown here - actuator 2 around the respective sun 7 . 8th ,

To 3 is a second position of the respective planetary gear set 4 . 5 at the respective sun 7 . 8th shown. In this second position, the ratio of the planetary gear is +1.

From the into the 2 and 3 illustrated rolling circles 4a . 4b . 5a . 5b . 7a . 8a It can be seen that a first tooth plane exclusively round gears, namely the first planetary gear set 4 as well as the first sun 7 includes, wherein a second tooth plane exclusively non-circular gears, namely the second planetary gear set 5 as well as the second sun 8th includes. A match of the rolling circles 4a . 4b . 5a . 5b of the first and second planetary gear sets 4 . 5 causes an automatic standstill of the planetary gear 2 , Thus, the agreement of the rolling circles 4a . 4b . 5a . 5b of the first and second planetary gear sets 4 . 5 a zero crossing. A stepwise adjustment movement of the actuator assembly is realized in each case until the zero pass. Advantageously, no holding current is thus needed to generate a holding torque. The planetary gear thus has a high gear ratio and high efficiency.

LIST OF REFERENCE NUMBERS

1

 actuator

2

 planetary gear

3

 mechanism

4

 first planetary gear set

4a, 4b

 pitch circles

5

 second planetary set

5a, 5b

 pitch circles

6

 planet carrier

7

 first sun

8th

 second sun

9

 output shaft

10

 drive shaft

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4788891 A1 [0002]

Claims (9)

Actuator assembly comprising an actuator ( 1 ), a planetary gear ( 2 ) as well as one from the actuator ( 1 ) mechanism to be operated ( 3 ), wherein the planetary gear ( 2 ) has a variable, periodically changing translation and at least indirectly with the actuator ( 1 ), further wherein the planetary gear ( 2 ) a first planetary gear set ( 4 ) with respective round rolling circles ( 4a . 4b ), and a second planetary gear set ( 5 ) with respective non-circular rolling circles ( 5a . 5b ), and wherein a match of the rolling circles ( 4a . 4b . 5a . 5b ) of the first and second planetary gear set ( 4 . 5 ) an automatic standstill of the planetary gear ( 2 ), whereby a stepwise adjusting movement of the actuator assembly in each case until the agreement of the rolling circles ( 4a . 4b . 5a . 5b ) of the first and second planetary gear set ( 4 . 5 ) is realized. Actuator arrangement according to claim 1, characterized in that the planetary gear ( 2 ) is designed as a plus gear. Actuator arrangement according to claim 1, characterized in that the first planetary gearset ( 4 ) rotatably with the second planetary gear set ( 5 ) is trained. Actuator arrangement according to claim 1, characterized in that the two planetary gear sets ( 4 . 5 ) rotatable on a common planet carrier ( 6 ) are stored. Actuator arrangement according to claim 4, characterized in that the common planet carrier ( 6 ) at least indirectly with the actuator ( 1 ) connected is. Actuator arrangement according to claim 1, characterized in that the first planetary gearset ( 4 ) with a first sun ( 7 ) and the second planetary gear set ( 5 ) with a second sun ( 8th ) combs. Actuator arrangement according to claim 6, characterized in that one of the two suns ( 7 . 8th ) is stationary and the other of the two suns ( 8th . 7 ) with an output shaft ( 9 ) connected is. Actuator assembly according to claim 6, characterized in that the from the actuator ( 1 ) mechanism to be operated ( 3 ) is a level control for a motor vehicle. Actuator assembly according to claim 6, characterized in that the from the actuator ( 1 ) mechanism to be operated ( 3 ) is a seat adjustment for a motor vehicle.

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