DE102013216411B4 - Transmission for a positioning actuator - Google Patents

Abstract

Transmission for a positioning actuator, the transmission at least comprising an input shaft (1), an output shaft (2), a first planetary gear set (PR1), a second planetary gear set (PR2) and a third planetary gear set (PR3), the input shaft (1) having a sun gear ( S1) of the first planetary gear set (PR1), the first planetary gear set (PR1), the second planetary gear set (PR2) and the third planetary gear set (PR3) being arranged coaxially with the input shaft (1), and a planet carrier (PT1) of the first Planetary gear set (PR1) is coupled to a housing (G), characterized in that a planet carrier (PT2) of the second planetary gear set (PR2) is connected to the output shaft (2), that the third planetary gear set (PR3) has a first planet carrier (PT3.1 ) and a second planetary carrier (PT3.2), and a ring gear (H2) of the second planetary gear set (PR2) via a fourth shaft (4) with the first planetary carrier (PT3.1) of the third planetary gear set (PR3) un d the second planet carrier (PT3.2) of the third planetary gear set (PR3) is connected and that a second ring gear (H3.2) of the third planetary gear set (PR3) is connected to the output shaft (2).

Description

The present invention relates to a transmission for a positioning actuator, as is used, for example, in aviation to adjust a part, for example a control surface or a high-lift surface of an aircraft.

The DE 3590370 T1 discloses a rotary actuator with multi-stage gear. This rotary actuator features a multi-speed gearbox with multiple balanced compound differentials for multi-speed output. The multi-speed geared rotary actuator includes a compact assembly of matched compound differentials that form multiple output stages. Axially aligned tubular planetary gear shafts of compound differentials have a common support running through them that reduces deflection at the ends of the planetary gear shafts, thereby increasing the load capacity of each stage.

In aviation in particular, so-called control actuators often have to perform control tasks with high external loads. Actuation tasks are to be understood, for example, as the actuation and adjustment of aircraft control surfaces, in particular of adjustable wing segments for changing the direction or for changing the lift of the wing. Especially in aviation, a low weight, a small installation space requirement and a high power density with a high degree of efficiency are of particular importance.

The document US 1,059,450A discloses a combination of a non-rotatable fixed-sided housing, an input shaft and an output shaft coaxial therewith, each journaled in the fixed sides of the housing. A pinion gear is located in the housing and on the drive shaft. In addition, trunnions are provided which are carried by one side of the housing and are thereby supported against physical movement. In addition, idler gears are provided on the respective journals and an internally toothed rotatable gear meshing with the idler gears. Drive power is transmitted between the internally toothed gear and the output shaft.

The U.S. 2012/0 231 923 A1 discloses a modular powertrain comprising an input shaft coupled to and driven by a source of applied torque, an output shaft coupled to and driving a load, a central support structure attached to a support bed panel, and an aperture for passing the output shaft therethrough, and a split link planetary gear system mounted on a first axial side of the central support structure. The planetary gear system includes a high torque stage (A) and a low torque stage (B). The planetary gear system is configured with a split connection to transmit torque from the input shaft to the output shaft through the high torque stage and the low torque stage. Stage (A) includes two adjacent arrays of starwheels placed within a closed truss with opposing walls. Each star wheel array consists of a plurality of star wheels supported by flexure pins which are cantilevered from an associated wall of the closed beam. Each of the star gears rotatably meshes with a common ring gear coupled to the input shaft. Each of the star gears is also rotatably engaged to a common sun gear coupled to stage (B). The load on a second axial side of the central support structure is coupled opposite the split compound planetary gear system, the load being coupled to and driven by the output shaft passing through the opening in the central support structure.

Also revealed U.S. 2010/0 304 913 A1 a gear change mechanism comprising a first planetary gear set comprising a first sun gear, a plurality of first planet gears, a first planet carrier and a first ring gear, wherein one of the first sun gear and the first ring gear comprises a first input and the other of the first sun gear and the first Ring gear includes a first output. Further, the gear change mechanism includes a second planetary gear set including a second sun gear, a plurality of second planet gears, a second planet carrier and a second ring gear, wherein one of the second sun gear and the second ring gear includes a second input and the other of the second sun gear and the second Ring gear includes a second output. There is also a power input connection for drivingly connecting the first input to an output from a power source and a drive assembly directly coupling the first output to the second input to transfer drive from the first output to the second input. The first and second planetary gear sets are drivingly coupled such that the first and second outputs are driven in opposite rotational directions. The speed change mechanism further includes a sleeve ring, a first one-way clutch for transmitting drive from the first output to the sleeve ring only in a first rotational direction, and a second one-way clutch for transmitting drive from the second output to the sleeve only in the first direction of rotation. The sleeve ring surrounds the first and second planetary gear sets.

The invention is therefore based on the object of proposing a transmission for a positioning actuator which has a high transmission ratio and at the same time has a high overall efficiency with optimized external dimensions and space requirements.

The object is achieved with a transmission for a positioning actuator according to patent claim 1, wherein the transmission is connected to at least one input shaft, one output shaft, a first planetary gear set, a second planetary gear set and a third planetary gear set, and the input shaft is connected to a sun gear of the first planetary gear set.

In this context, a transmission designates an arrangement of gear wheels, wherein, depending on the design of the transmission, there is a reversal of direction of rotation and/or a change in speed between a transmission input and a transmission output. In addition, a transmission can also be used to transmit a rotational movement from a first shaft to a second shaft, even if the first shaft and the second shaft are not arranged coaxially with one another.

In the following, a shaft is not to be understood exclusively as a cylindrical, rotatably mounted machine element for the transmission of torque, but rather also as general connecting elements that connect individual components or elements to one another.

Connected to one another is to be understood as meaning that there is a permanent, fixed connection between two elements, as a result of which, for example, a rotational movement can be permanently transmitted from one component to the other component.

A planetary gear set preferably includes a sun gear, a planet carrier and a ring gear. Planetary gears are rotatably mounted on the planetary carrier and mesh with the toothing of the sun gear and/or with the toothing of the ring gear.

Below, a negative planetary gear set describes a single planetary gear set with a planet carrier on which the planet gears can be rotatably mounted, with a sun gear and with a ring gear, with the toothing of at least one of the planetary gears being connected to both the toothing of the sun gear and the toothing of the Ring gear meshes, whereby the ring gear and the sun gear rotate in opposite directions of rotation when the sun gear rotates with the planet carrier stationary. The use of planetary gear sets means that particularly compact transmissions can be implemented, which means that there is a great deal of freedom in the arrangement of the transmission.

The elements of a planetary gear set are understood to mean, in particular, the sun gear, the ring gear, the planet carrier and the planetary gears of the planetary gear set. A plus planetary gear set differs from the minus planetary gear set just described in that the plus planetary gear set has inner and outer planet gears which are rotatably mounted on the planet carrier. The toothing of the inner planetary gears meshes with the toothing of the sun gear on the one hand and with the toothing of the outer planetary gears on the other hand. The toothing of the outer planet gears also meshes with the toothing of the ring gear. As a result, when the planet carrier is stationary, the ring gear and the sun gear of the planetary gear set rotate in the same direction of rotation.

Furthermore, the first planetary gear set, the second planetary gear set and the third planetary gear set are arranged coaxially to the drive shaft, with a planet carrier of the first planetary gear set being coupled to a housing.

A housing is to be understood, for example, as the transmission housing of the transmission, but it should preferably be expressed that the planet carrier of the first planetary gear set is arranged in the transmission in a rotationally fixed manner by being connected to the housing.

A coaxial arrangement of the first planetary gear set, the second planetary gear set and the third planetary gear set is preferably understood here to mean that the first planetary gear set, the second planetary gear set and the third planetary gear set are each constructed symmetrically with respect to an axis of rotation running through a center point of the respective planetary gear set are and the respective axes of rotation of the individual planetary gear sets are arranged coaxially to the drive shaft.

More preferably, a ring gear of the first planetary gear set is connected to a sun gear of the second planetary gear set via a third shaft.

In addition, according to the invention, a planet carrier of the second planetary gear set is connected to the output shaft.

In addition, a transmission input speed n1 is preferably present at the input shaft and a transmission output speed n2 is present at the output shaft, with the transmission output speed n2 being lower than the transmission input speed n1.

More preferably, the direction of rotation is reversed between the input shaft and the output shaft.

This means that the direction of rotation of the input shaft is opposite to the direction of rotation of the output shaft.

In addition, according to the invention, the third planetary gear set has a first planetary carrier and a second planetary carrier. According to the invention, a ring gear of the second planetary gear set is connected via a fourth shaft to the first planet carrier of the third planetary gear set and the second planet carrier of the third planetary gear set.

In a preferred embodiment, the first planet carrier of the third planetary gear set is arranged between the second planetary gear set and the second planet carrier of the third planetary gear set.

More preferably, a first ring gear of the third planetary gear set is coupled to the housing.

Coupled means that the elements mentioned are connected to one another. The elements, such as the first ring gear of the third planetary gear set and the housing here, can be connected directly to one another. However, it is also conceivable that a further connecting element, for example a shaft, is arranged between the two elements to be connected.

In addition, according to the invention, a second ring gear of the third planetary gear set is connected to the output shaft.

In a further preferred embodiment, the third planetary gear set is designed as a plus planetary gear set.

In addition, a ring gear of the third planetary gear set is preferably connected to the housing.

As already mentioned at the outset, the connection to the housing means that the element connected thereto is arranged in a rotationally fixed manner. A rotation of the ring gear of the third planetary gear set, for example, is therefore not possible.

According to a further aspect of the present invention, a positioning actuator is proposed which has a gear mechanism of the type mentioned at the outset.

• 1: eine schematische Ansicht einer bevorzugten Ausführungsform des erfindungsgemäßen Getriebes;
• 2: eine schematische Ansicht eines erläuternden Beispiels des Getriebes.

The invention is explained in more detail below by way of example with reference to the attached figures. Show it:

• 1 : a schematic view of a preferred embodiment of the transmission according to the invention;
• 2 : a schematic view of an explanatory example of the transmission.

1 shows a preferred embodiment of the transmission in a schematic representation. The transmission includes a first planetary gear set PR1, a second planetary gear set PR2 and a third planetary gear set PR3. The three planetary gear sets PR1, PR2, PR3 are arranged rotationally symmetrically with respect to a drive shaft 1 and a driven shaft 2, respectively. In addition, the first planetary gear set PR2, the second planetary gear set PR2 and the third planetary gear set PR3 are starting on one side of the drive shaft 1 in the order first planetary gear set PR1, second planetary gear set PR2, third planetary gear set PR3 coaxial with the drive shaft 1 or an imaginary extension of the drive shaft 1 arranged.

The drive shaft 1 is connected to a sun gear S1 of the first planetary gear set PR1. The toothing of the sun gear S1 of the first planetary gearset PR1 meshes with the toothing of the planetary gears of a planet carrier PT1 of the first planetary gearset PR1. The toothing of the planet gears of the planet carrier PT1 of the first planetary gear set PR1 also meshes further with the toothing of a ring gear H1 of the first planetary gear set PR1. The planet carrier PT1 of the first planetary gear set PR1 is connected to a housing G, as a result of which it is arranged in the transmission in a rotationally fixed manner.

The ring gear H1 of the first planetary gear set PR1 is further connected via a third shaft 3 to a sun gear S2 of the second planetary gear set PR2. The toothing of the sun gear S2 meshes with the toothing of the planetary gears of a planet carrier PT2 of the second planetary gear set PR2, which further meshes with the toothing of a ring gear H2 of the second planetary gear set PR2. The planet carrier PT2 is connected to the output shaft 2.

The third planetary gear set PR3 has a first planetary carrier PT3.1 and a second planetary carrier PT3.2. Also has the third planetary gear set PR3 in assignment to the respective Gen planetary carriers PT3.1, PT3.2 via a first ring gear H3.1 and a second ring gear H3.2.

The ring gear H2 of the second planetary gearset PR2 is connected via a fourth shaft 4 to the first planetary carrier PT3.1 of the third planetary gearset PR3 and beyond that to the second planetary carrier PT3.2 of the third planetary gearset PR3, with the first planetary carrier PT3.1 of the third Planetary gear set PR3 is also connected via the fourth shaft 4 to the second planet carrier PT3.2 of the third planetary gear set PR3. The toothing of the first ring gear H3.1 of the third planetary gear set PR3 meshes with the toothing of the planet gears of the first planetary carrier PT3.1 of the third planetary gear set PR3. The first ring gear H3.1 of the third planetary gear set PR3 is further connected to the housing G. Thus, the first ring gear H3.1 of the third planetary gear set PR3 is also arranged in the transmission in a torque-proof manner. The teeth of the planet gears of the second planet carrier PT3.2 of the third planetary gear set PR3 meshes with the teeth of the second ring gear H3.2 of the third planetary gear set PR3. The second ring gear H3.2 of the third planetary gear set PR3 is also connected to the output shaft 2. The first planet carrier PT3.1 and the first ring gear H3.1 of the third planetary gear set PR3 are arranged spatially between the second planetary gear set PR2 and the second planet carrier PT3.2 or the second ring gear H3.2 of the third planetary gear set PR3.

The first planetary gear set PR1 and the second planetary gear set PR2 are each designed as a minus planetary gear set, while the third planetary gear set PR3 is designed as a so-called stepped planetary gear set. This means that the planet gears of the third planetary gear set PR3 are arranged on a common planet carrier PT3.1, PT3.2. It does not have a sun gear. To support the first planetary carrier PT3.1 and the second planetary carrier 3.2 of the third planetary gear set PR3, a respective support or bearing of the first planetary carrier PT3.1 or the second planetary carrier PT3.2 is to increase the stability of the wheel set or to increase the functionality conceivable on the output shaft 2. The support must be such that, for example, a rotary bearing prevents a rotary movement or torque from being transmitted between the respective planet carrier PT3.1, PT3.2 of the third planetary gear set PR3 to the output shaft 2 and vice versa.

2 shows an explanatory example of the transmission in a schematic representation. The transmission also includes a first planetary gear set PR1, a second planetary gear set PR2 and a third planetary gear set PR3; the design and arrangement of the first planetary gear set PR1, the second planetary gear set PR2 and the respective connection to the drive shaft 1, the housing G, the third shaft 3 and the fourth shaft 4 is with the in 1 described arrangement and connection identical.

In contrast to the first planetary gear set PR1 and the second planetary gear set PR2, the third planetary gear set PR3' is not designed as a minus planetary gear set, but as a plus planetary gear set. The third planetary gear set PR3' also has a first planetary carrier PT3.1' and a second planetary carrier PT3.2`. In contrast to the 1 In the described arrangement of the third planetary gear set PR3', the second planetary carrier PT3.2` of the third planetary gear set PR3' is arranged above the first planetary carrier PT3.1'. In this context, above means that the first planetary carrier PT3.1' is at a smaller distance from the output shaft 2 than the second planetary carrier PT3.2' of the third planetary gear set PR3'. The third planetary gear set PR3' has, in contrast to the in 1 described arrangement via a sun gear S3 ', which is connected to the output shaft 2. The toothing of the sun gear S3' of the third planetary gear set PR3' meshes with the toothing of the planetary gears of the first planet carrier PT3.1' of the third planetary gear set PR3', with these further meshing with the toothing of the planetary gears of the second planetary carrier PT3.2` of the third planetary gear set PR3 ' combs. The toothing of the planet gears of the second planetary carrier PT3.2` of the third planetary gear set PR3' further meshes with the toothing of a third ring gear H3' of the third planetary gear set PR3'. The ring gear H3' of the third planetary gear set PR3' is further connected to the housing G, as a result of which it is arranged in the transmission in a rotationally fixed manner. The ring gear H2 of the second planetary gear set PR2 is, as in 1 described, connected via the fourth shaft 4 to the first planetary carrier PT1 'and the second planetary carrier PT3.2 of the third planetary gear set PR3', the first planetary carrier PT3.1 'via the fourth shaft 4 also being connected to the second planetary carrier PT3.2' of the third planetary gear set PR3 is connected. In contrast to the in 1 However, in the arrangement described, the fourth shaft 4 does not pass through the first planet carrier PT3.1 of the third planetary gear set PR3, but instead has a branch between the second planetary gear set PR2 and the third planetary gear set PR3', as a result of which the one above the first planet carrier PT3.1' arranged second planet carrier PT3.2 `of the third planetary gear PR3 'are connected to each other.

2 shows only an illustrative example not belonging to the invention as literally defined in the claims.

Reference List

1

drive shaft

2

output shaft

3

third wave

4

fourth wave

G

Housing

H1

ring gear PR1

H2

ring gear PR2

H3, H3'

ring gear PR3

PR1

first planetary gear set

PR2

second planetary gear set

PR3, PR3'

third planetary gear set

PT1

Planet carrier PR1

PT2

Planet carrier PR2

PT3.1

Planet carrier PR3

PT3.1'

first planet carrier PR3'

PT3.2`

second planet carrier PR3'

S1

Sun gear PR1

S2

Sun gear PR2

S3

Sun gear PR3

Claims (6)

Transmission for a positioning actuator, the transmission at least comprising an input shaft (1), an output shaft (2), a first planetary gear set (PR1), a second planetary gear set (PR2) and a third planetary gear set (PR3), the input shaft (1) having a sun gear ( S1) of the first planetary gear set (PR1), the first planetary gear set (PR1), the second planetary gear set (PR2) and the third planetary gear set (PR3) being arranged coaxially with the input shaft (1), and a planet carrier (PT1) of the first Planetary gear set (PR1) is coupled to a housing (G), characterized in that a planet carrier (PT2) of the second planetary gear set (PR2) is connected to the output shaft (2), that the third planetary gear set (PR3) has a first planet carrier (PT3. 1) and a second planet carrier (PT3.2), and a ring gear (H2) of the second planetary gear set (PR2) via a fourth shaft (4) with the first planet carrier (PT3.1) of the third planetary gear set (PR3) and the second planet carrier (PT3.2) of the third planetary gear set (PR3) and that a second ring gear (H3.2) of the third planetary gear set (PR3) is connected to the output shaft (2). Transmission for a Stellaktuator according claim 1 , characterized in that a ring gear (H1) of the first planetary gear set (PR1) via a third shaft (3) with a sun gear (S2) of the second planetary gear set (PR2) is connected. Transmission for a positioning actuator according to one of the preceding claims, characterized in that a transmission input speed n1 is applied to the drive shaft (1) and a transmission output speed n2 is applied to the output shaft (2), the transmission output speed n2 being lower than the transmission input speed n1. Transmission for a setting actuator according to one of the preceding claims, characterized in that the direction of rotation is reversed between the input shaft (1) and the output shaft (2). Transmission for a setting actuator according to one of the preceding claims, characterized in that the first planet carrier (PT3.1) of the third planetary gear set (PR3) between the second planetary gear set (PR2) and the second planetary carrier (PT3.2) of the third planetary gear set (PR3) is arranged. Transmission for a setting actuator according to one of the preceding claims, characterized in that a first ring gear (3.1) of the third planetary gear set (PR3) is coupled to the housing (G). 7. positioning actuator at least comprising a transmission according to any one of the preceding claims.

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