DE102015204504B4 - Assembly, in particular actuator with a friction device - Google Patents

Abstract

Assembly, in particular actuator with a friction device and with at least two relatively rotatable components, for the actuation of a clutch of a vehicle, wherein the second component (2) radially within the first component (1) is arranged axially offset and a wrap spring (3) between the first and the second component (1,2) sits and with a first end non-rotatably or frictionally connected to the first component in a first region (A) and with a second end frictionally connected to the second component in a second region (B) in that between the first region (A) of the wrap spring (3) and the second region (B) of the wrap spring (3) a first and second transition region (A ', B') into a first and second partial region (A *, B * ), wherein the partial regions (A *, B *) have different diameters to the first and second regions (A, B) of the wrap spring (3), characterized in that the first region (A) in the first component (1 ) lying over a first transitional region (A ') into a first subregion (A *), to which a transition region (C') adjoins, which connects the first subregion (A *) to the second subregion (B *) to which a further transition region (B ') of the region (B) on the second component (2) lying adjacent.

Description

The invention relates to an assembly, in particular actuator with a friction device with at least two relatively rotatable components, which is used in particular for the actuation of a clutch of a motor vehicle and is at least part of a transmission and / or actuator.

Actuators are used for example for actuating a clutch of a vehicle and can convert the rotational movement of a component into an axial movement of another component. The actuator itself can be any type of linear actuator, z. As PWG actuator (PWG = Planetenwälzgewindsspindeltrieb), hydraulic slave cylinder, etc ..

Planetenwälzgewindespindeltriebe (PWG) are formed from a spindle, a spindle nut and between them arranged over the circumference, received in a planet carrier Planetenwälzkörpern. Here, the spindle, spindle nut and Planetenwälzkörper on profiling to transmit a rotational movement between the spindle and spindle nut, wherein one of the components - spindle or spindle nut - rotatably driven and the other component in a rotationally fixed arrangement along the longitudinal axis of the spindle by one of the set translation corresponding Axialweg is relocated. Here, the Planetenwälzkörper two different profile sections, which mesh on the one hand with the spindle and on the other hand with the spindle nut, the profile sections on the Planetenwälzkörper grooved and the other profile sections on the Planetenwälzkörper are generally grooved and depending on the embodiment, a complementary threaded portion on the spindle or the spindle nut and according to the groove portion is arranged on the other component. As a result, compared to a direct recording of the spindle on the spindle nut translations are achieved with which per spindle rotation with less feed a higher force is possible.

From the EP 320 621 A1 For example, a PWG is known in which the spindle has a thread and the spindle nut grooves, on which roll each planetary rolling elements by means of correspondingly complementarily formed profile sections. Here, the axially fixed and rotatably driven, for example by an electric motor spindle relative to the rotatably mounted spindle nut is rotated, so that the spindle nut is forcibly displaced axially and by the frictional rolling of the planetary body in the grooves of the spindle nut. This results in the Axialweg the spindle nut proportional to the speed of the spindle movement. To this end, according to planetary gears of the planet carrier rotates with the planetary rollers at half speed or another ratio, depending on the design of the diameter of the rotating component, namely spindle or spindle nut.

The DE 10 2010 047 800 A1 shows an application of a Planetenwälzgetriebes, in which designed as a piston of a master cylinder Aktorteil a Hydrostataktors axially fixed to the rotatably and axially displaceably arranged spindle is coupled, wherein the axially fixed spindle nut is rotationally driven by an electric motor, so that upon rotation of the spindle nut spindle and Spindle nut are shifted against each other along the Axialwegs. Since the piston accommodating and forming a pressure chamber with this cylinder housing is fixed and the spindle nut is axially supported on this, the piston builds depending on the rotary drive of the spindle nut pressure, for example for actuation of automotive components such as brakes, friction clutch and the like. It is particularly desirable for friction clutches to quickly bridge a clearance with low load request by means of a high pitch and be able to apply high loads with an electric motor with low power in the effective range of the friction clutch by means of a small slope.

In example, driven by an electric motor efficiency-optimized spindle drives (eg. PWG), especially in actuators, such as hydrostatic clutch actuators (Hydrostatic Clutch Actuator - abbreviated HCA), which work against a load, such as a clutch characteristic, there is a problem that when a required holding a Position holding current and thus a holding torque in the electric motor is required because the spindle drive (eg in a PWG) is not self-locking. In a PWG in a HCA with rotatable ring gear nut with driven spindle, on which the axial movement (relative to the spindle) is tapped, takes place in an ideal rolling movement (as in a toothed planetary gear / no slip) an additional reduction of the spindle pitch, this is varied by of spindle and / or planetary roller diameter within limits freely selectable.

A decisive disadvantage of such actuators is that they require a permanent holding current or, in the event of a power failure / fault (eg cable break, plug drop), the position can not be maintained. If the clutch is pressed by the actuator, then there is a great danger that the clutch will close unintentionally.

It is also known the use of wrap springs, for example for clutches. A wrap spring usually consists of a metallic wire which extends in several turns around a cylindrical part. Between this spring and the cylindrical part a friction force acts upon rotation of the cylindrical part. This can be influenced by tightening or releasing the wrap spring.

A wrap spring clutch usually consists of a wound on a shaft or a cylindrical body coil spring, which is fixed on one side to the drive. The entrainment effect is based on the fact that the driving torque with each turn amplified by the friction and adds up. This increases because of the wrap at the same time the friction causing this force. In the opposite direction occurs only a slight friction - the spring slightly increases its diameter, but does not wrap. Due to their friction remaining in free-running operation, the wrap spring is also used for slipping clutches. As a freewheeling element, it has a self-reinforcing (blocking) effect in one direction and a repeal of this function in the other direction, the spring only has to be rotated against its basic friction.

Such Schlingfederkupplungen are generally for example from the US 2,984,325 , of the FR 2 283 357 A1 , of the US 4,763,764 A and US Pat. No. 2,895,578 known.

From the publication DE 10 2007 047 394 A1 For example, a torsional vibration damper is known which has at least two counter to the action of a damping device with circumferentially acting energy storage to each other rotatable parts, one of which is connectable to a prime mover and the other with a driven shaft, wherein between the two parts additionally with the Damping device is provided in series connected torque limiter, which is effective at least in one of the relative rotational directions between the two parts and at least one Schlingenfederkupplung includes, which acts upon reaching a predetermined angle of rotation between the two parts as a freewheel and at least one loop spring element comprises. This solution is characterized in that at least one end of the loop spring element is non-rotatably connected to a ring element which has support regions for the energy storage devices acting in the circumferential direction and / or activation regions for the freewheeling effect.

In a not yet published technical solution of the applicant, an assembly with a friction device with at least two mutually rotatable components, in particular for the actuation of a clutch of a vehicle, proposed in which between the relatively rotatable components at a relative rotation of the components the efficiency / the friction influencing coil spring is arranged. At least partially, the helical spring forms a wrap spring, which may be a simple wrap spring, a double wrap spring or a loop torsion spring. The Doppelschlingfeder described here has two effective areas, which are arranged axially one behind the other, since a nesting of shaft and sleeve is not possible.

Due to space constraints and production-related wall thicknesses of the components nesting of shaft and sleeve is not always possible. This has disadvantages, as it comes in the transition areas (chamfers on the shaft or in the pot) to so-called edge beams. These areas are not static contact points but circumferential friction contacts resulting in a relative movement / friction between wrap and shaft or sleeve / pot. Therefore, at these points with increased wear and consequently be expected to loss of function.

The object of the present invention is to find an assembly, in particular actuator with a friction device with a loop spring geometry with direction-dependent friction torque that does not allow nesting of shaft and sleeve / pot, the above-mentioned disadvantages are to be eliminated.

The object is solved by the features of the first claim. Advantageous embodiments emerge from the subclaims.

The invention relates to an assembly, in particular actuator with a friction device and with at least two relatively rotatable components, in particular for the actuation of a clutch of a vehicle, wherein the second component is axially offset axially within the first component and a wrap spring between the first and the second component sits and with a first end non-rotatably or frictionally connected to the first component in a first region and a second end frictionally connected to the second component in a second region. Between the first region of the wrap spring and the second region of the wrap spring are a first and second transition region in a first and second portion, wherein the portions have different diameter to the first and second portions of the wrap spring. In this case, the first portion reaches or falls below the diameter of the first portion of the wrap spring. The second Part area area reaches or exceeds the diameter of the second area of the wrap spring.

In this case, the first subregion is wound radially inward and the second subregion is wound radially outward.

The assembly has no axial overlap region between the first and second components, the first component preferably being a sleeve and the second component being a shaft. The assembly of the wrap spring takes place in the first region of the wrap spring within the sleeve wherein the first portion in the axial direction begins after the sleeve and ends in front of the shaft. The second subarea, which can overlap the shaft, adjoins the first subarea.

The structure of the individual areas of the wrap spring is therefore as follows. The first region lies within the sleeve, with a first transition region leading to a first partial region with a radially inwardly pointing winding. This subregion is followed by a transition region into a further subregion, which has a radially outwardly widened winding. Subsequent to this subarea, there follows a further transition area which leads into the second area, which is in operative connection with the shaft.

With the help of the loop spring geometry according to the invention so-called edge beams can be avoided, which prevents high wear and loss of function.

The invention will be explained in more detail with reference to embodiments and accompanying drawings.

• 1 Schlingfeder in verbautem Zustand,
• 2 Schlingfeder in freiem Zustand,
• 3 Detailansicht der optimierten Geometrie der Schlingfeder.

Show it:

• 1 Wrap in installed condition,
• 2 Wrap in free state,
• 3 Detail view of the optimized geometry of the wrap spring.

According to 1 an assembly is shown with a friction element. The assembly consists of a first component in the form of a sleeve 1 , a second component in the form of a shaft 2 and a wrap 3 which is seated between the first and the second component 1,2 and with a first end non-rotatably or frictionally engaged with the first component in a first region A and with a second end frictionally engaged with the second component in a second region B connected is. This is the area A inside the sleeve 1 , where the outside diameter d3 the wrap spring 3 with the inside diameter D1 the sleeve 1 corresponds. In the second area B correspond to the outer diameter d2 the wave 2 with the inside diameter D3 the wrap spring 3 , where the outside diameter d3 the wrap spring 3 in the area A smaller than in the area B which is above the shaft 2 lies.

The sleeve 1 is axially offset from the shaft 2 arranged, with no axial overlap area is present. At the first area A is arranged following a first transitional area A ', which is a subarea A * leads. The subarea A * is wound radially inward and therefore smaller in its outer diameter than in the partial area A , As a result, the formation of so-called edge beams is avoided. The first section A * follows the subarea B * which is above the beginning of the wave 2 lies. Here is the subarea B * wrapped radially outwards and thus reaches the largest outer diameter of the wrap spring 3 , Over a transition region B 'is the outer diameter D3 the wrap spring is reduced in area B, causing the wrap spring 3 with the wave 2 is operatively connected via a frictional connection.

In 2 are the individual areas of the wrap 3 shown in the free state. The winding diameter of the wrap spring 3 is not constant,
the winding profile knows the area A on, in the installed state in the sleeve 1 is mounted as well as the area B , in the installed state on the shaft 2 is mounted. Furthermore, the transition area A ', B' is between the areas A and B as well as the subareas A * . B * shown. The transition area A 'leads from area A in area A * , where the area A * in free condition, the diameter of the built-in spring in the area A reached or fallen below.

Following area A * there is a transition area C 'in the area B * ,

The area B * reaches or exceeds the diameter of the built-in spring in the free state in the area B ,

Following area B * there is a transition area B 'which in the area B leads.

A closer view of the radially inner and outer windings is in 3 shown. Here, the radially inwardly facing winding between sleeve 2 and wave 1 arranged. A concern of the wrap 3 on the sleeve 1 in the area A * is thus avoided. The subarea B * lies radially outwardly wound from the shaft 2 spaced and thus avoids the emergence of edge beams.

It is thus ensured an optimized geometry of the wrap in a nearly undeformed area in the installed state to prevent edge beams.

LIST OF REFERENCE NUMBERS

1

shell

D1

Inner diameter of the sleeve

2

wave

d2

Outer diameter of the shaft

3

wrap

d3

Outer diameter of the wrap spring

D3

Inner diameter of the wrap spring

A

First area of the wrap

A '

First transition area

A *

First section

B

Second area of the wrap

B '

Second transition area

B *

Second subarea

C '

Transition between A * and B *

Claims (10)

Assembly, in particular actuator with a friction device and with at least two relatively rotatable components, for the actuation of a clutch of a vehicle, wherein the second component (2) radially within the first component (1) is arranged offset axially and a wrap spring (3) between the first and the second component (1,2) sits and with a first end non-rotatably or frictionally connected to the first component in a first region (A) and with a second end frictionally connected to the second component in a second region (B) in that between the first region (A) of the wrap spring (3) and the second region (B) of the wrap spring (3) a first and second transition region (A ', B') into a first and second partial region (A *, B * ), wherein the partial regions (A *, B *) have different diameters to the first and second regions (A, B) of the wrap spring (3), characterized in that the first region (A) in the first component (1 ) l via a first transition region (A ') leads into a first subregion (A *), adjoining this a transition region (C') which connects the first subregion (A *) to the second subregion (B *) at which via a further transition region (B ') of the region (B) on the second component (2) lying adjacent. Assembly after Claim 1 , characterized in that the first portion (A *) reaches or falls below the diameter of the first region (A) of the wrap spring (3). Assembly after Claim 1 , characterized in that the second partial region region (B *) reaches or exceeds the diameter of the second region (B) of the wrap spring (3). Assembly according to one of Claims 1 to 3 , characterized in that the wrap spring (3) in the first portion (A *) is wound radially inwardly. Assembly according to one of Claims 1 to 4 , characterized in that the wrap spring (3) in the second portion (B *) is wound radially outward. Assembly according to one of Claims 1 to 5 , characterized in that between the first and second component (1,2) no axial overlap region is present, wherein the first component is preferably a sleeve (1) and the second component is a shaft (2). Assembly after Claim 6 , characterized in that the first region (A) of the wrap spring (3) is located inside the sleeve (1) and the first portion (A *) begins in the axial direction only after the sleeve (1) and in front of the shaft (2). ends, wherein the second portion (B *) connects to the first portion (A *), which can overlap the shaft (2). Assembly according to one of Claims 1 to 6 , characterized in that the wrap spring (3) in the first region (A) inside the sleeve (1) rests, wherein the inner diameter (D1) of the sleeve (1) equal to the outer diameter (d3) of the wrap spring (3) in the first region (A) is. Assembly according to one of Claims 1 to 7 , characterized in that the wrap spring (3) in the second region (B) rests on the shaft (2), wherein the outer diameter (d2) of the shaft (2) equal to the inner diameter (D3) of the wrap spring (3) in the second region ( B) is. Assembly after Claim 1 , characterized in that the first region (A) lying in a sleeve (1) leads via a first transition region (A ') into a first partial region (A *), to which a transition region (C') adjoins, which connects the first partial region (A *) connects to the second subregion (B *), at which the region (B) adjoins a shaft (2) via a further transition region (B ').

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