DE102013210692A1 - Active storage device - Google Patents

Abstract

The invention relates to an active bearing device (1) comprising a bearing device (2) which has at least one bearing ring (5, 6), the bearing device (2) and / or the bearing ring (5, 6) having a bearing axis (L) defined, as well as from an actuator device (3) for generating an actuator force (A) and from a conversion device (4) for converting the actuator force (A) in an axial direction with respect to the bearing axis (L) on the bearing ring (5, 6) acting force (S). According to the invention, the actuator device (3) is designed as an EAP actuator device with electroactive polymers.

Description

Field of the invention

The invention relates to an active storage device according to the preamble forming features of patent claim 1, and it is particularly advantageous for spindle bearings of machine tools applicable.

Background of the invention

In many cases, bearing systems are installed in constructions, the exact final position and, if necessary, a necessary preload of the bearing system being set during installation. It is also known to mechanically adjust bearing systems with the aid of a clamping nut after installation with respect to the bias in order to match the storage system as best possible to the application.

An already known development provides that the preload of bearing systems is not statically adjusted, but the bias voltage via an actuator device, e.g. is adjustable during operation of the storage system.

In this context, the document discloses WO2012 / 097962 A2 , which is probably the closest prior art, a hydraulically preloaded roller bearing, wherein the rolling bearing can be biased by a hydraulically acting fluids within an elastomeric pressure ring variable during operation.

Object of the invention

The invention has for its object to provide an active storage device that allows easy integration into a design.

Description of the invention

This object is achieved by an active bearing device having the features of claim 1. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description and the accompanying drawings.

In the context of the invention, an active bearing device is proposed, which makes it possible to actively change the bearing preload during operation, in particular using external energy.

The active storage device comprises a bearing device, which is particularly preferably designed as a rolling bearing. In particular, the bearing device is realized as a radial roller bearing. The bearing device comprises at least one bearing ring, wherein the bearing ring preferably provides one or at least one rolling track for the rolling elements of the rolling bearing. In the most general embodiment of the invention, the bearing means may e.g. be realized as a roller bearing or as a ball bearing. The bearing device and / or the bearing ring defined by the rotation during operation a bearing axis.

Furthermore, the active bearing device comprises an actuator device for generating an actuator force. The actuator device particularly preferably generates an actuator stroke in the direction of the actuator force.

In addition, the active bearing device has a conversion device for implementing the actuator force, wherein the actuator force is converted into a restoring force, in particular transmitted, translated, stocky or converted, which acts in an axial direction with respect to the bearing axis directly or indirectly on the bearing ring. Thus, by the interaction of the actuator device and conversion device of the bearing ring in the axial direction with respect to the bearing axis is acted upon by the actuating force, in particular to adjust or influence the bias, in particular biasing force of the bearing device.

In the context of the invention it is proposed that the actuator device is designed as an EAP actuator device with electroactive polymers. In particular, the EAP actuator device may be integrally formed or comprise a plurality of sections. Electroactive polymers (EAP) are polymers that change shape upon application of an electrical voltage. In particular, the EAPs are electronic or ionic. The electroactive polymers are particularly preferably in a solid, in particular non-liquid and non-gaseous, state of aggregation.

The advantage of the invention can be seen in that the EAP actuator device can be actuated by electrical voltage, so that can be dispensed with complex and thus complex mechanical or hydraulic systems. Instead of a supply for mechanical or hydraulic energy, an electrical supply line for supplying the EAP actuator device is sufficient. The EAP actuator device or the electroactive polymers are also characterized by a large volume change ability, so that a robust implementation of the actuator force can be ensured with a simple mechanism.

Optionally, in addition, the EAP actuator device can be used as a pressure sensor for measuring the applied forces in order to measure the bearing preload. In this way, a control circuit, in particular a control circuit or control loop, are constructed to control the bearing preload. This leads to a space-saving, easily integrable, "intelligent" component.

In a preferred embodiment of the invention, the actuator force is radially aligned with respect to the bearing axis, wherein the conversion device is designed such that to transmit the radial actuator force in the axial force. There is thus a deflection of the radially oriented actuator force in the axially aligned actuating force. With this configuration, it is possible to save space in the axial direction and instead to let the EAP actuator device extend in the radial direction.

In this embodiment, it is particularly preferred that the EAP Aktoreinrich device is formed as a continuous ring or as a plurality of stack actuators. In training as a continuous ring, the EAP Aktoreinrich-tion is particularly easy to assemble and represents only a single component. However, should higher actuator forces be necessary, a plurality of stack actuators can be used, which are preferably aligned radially.

In a preferred embodiment of the invention, the conversion device is designed as a wedge mechanism. The wedge mechanism comprises movable in the radial direction to the bearing axis adjusting elements, wherein the adjusting elements are moved by the EAP actuator device. The adjusting elements have actuating surfaces acting in the axial direction, so that the radial actuator force is transmitted into the axial actuating force.

Particularly preferably, the conversion device comprises at least one clamping ring, wherein on the clamping ring opposing surfaces are arranged to the shelves. The counter surfaces can also form a common total area. By the movement of the adjusting elements in the radial direction, the support surfaces move relative to the opposing surfaces, wherein an implementation of the radial actuator force is carried out in the axial force by an angular adjustment of the opposing surfaces and / or the shelves with respect to a perpendicular to the bearing axis arranged radial plane.

In a preferred structural embodiment, the adjusting elements are each formed as a wedge segment, wherein the wedge segment occupies a wedge angle greater than zero with respect to a radial plane which is perpendicular to the bearing axis occupies. Alternatively or additionally, the counterpart surface may be formed as a wedge surface, wherein this assumes a wedge angle greater than zero relative to a radial plane perpendicular to the bearing axis.

It is conceivable that the adjusting element is designed for example as a ball, which is displaced along the wedge surface in the radial direction. However, it is particularly preferred that one or more wedge segments are moved as adjusting elements on the wedge surfaces or faces as counteracting surfaces in the radial direction, wherein the wedge angle of the wedge segments and the wedge surface is the same, resulting in a surface contact between the wedge segments and the wedge surfaces. This embodiment is particularly resistant to wear and robust, as always surfaces work against each other. Optionally, the wedge angles may be introduced by a differential amount greater than 0.2 ° and less than 5 ° to reduce cohesion or adhesion between the wedge segments and the opposing surfaces. Alternatively or additionally, surface dips, e.g. Beading or elevations are introduced into the shelves and / or counter surfaces.

In a possible development of the invention, the conversion device has two clamping rings, wherein each of the clamping rings carries a wedge surface and wherein the wedge segments are wedge-shaped on both sides or trapezoidal overall with respect to a perpendicular to the bearing axis arranged radial surface. In this embodiment, the wedge segment is realized on both sides, so that a higher axial stroke can be achieved by a radial movement of the actuating element.

In a preferred embodiment of the invention, the at least one clamping ring or one of the two clamping rings, but preferably both clamping rings, an end stop for the adjusting elements with deactivated EAP actuator device. This embodiment has the advantage that in case of failure of the power supply for the EAP actuator device, the active storage device goes into a defined operating position, so that, for example, an emergency operation of the active storage device despite a failure of the power supply is possible.

The EAP actuator device is designed so that it can build up pressure forces, but can not realize tensile forces. For this reason, it is preferred that the active bearing device comprises a spring means for biasing the adjusting elements, wherein the biasing force is directed against the direction of the actuator force. By this bias is ensured that the control elements are tracked in a deactivation of the EAP actuator device the Aktorhub the EAP actuator device and not undefined remain in an intermediate position.

As an alternative to the spring device, it is also possible to provide a further EAP actuator device whose pressure force direction is directed against the direction of the actuator force of the EAP actuator device. In this embodiment, the actuating element can be actively displaced in both radial directions and thus an axial actuating force can be built up in both axial directions.

It is possible within the scope of the invention that the bearing ring is formed as an outer ring or as an inner ring. In these embodiments, it is thus feasible to bring the bias on the outer ring or on the inner ring.

Furthermore, it is possible within the scope of the invention for the EAP actuator device to be arranged radially on the inside to the adjusting elements or radially outside to the adjusting elements. In the event that the EAP actuator device is arranged radially on the inside, the adjusting elements are actively moved radially outwards, in the event that the EAP actuator device is arranged radially on the outside, the adjusting elements are actively moved radially inward.

Moreover, it is possible within the scope of the invention to arrange the conversion device relative to the bearing device so that when the actuator force is increased, the biasing force in the bearing device is increased or decreased.

By means of these alternatives, several variants I-VIII of the active bearing device can be implemented, as can be seen from the following table:

alternatives I II III IV V VI VII VIII bearing ring outer ring 1 0 1 0 1 0 1 0 inner ring 0 1 0 1 0 1 0 1 Arrangement of the EAP actuator device Radially outside 1 1 0 0 1 1 0 0 Radially inside 0 0 1 1 0 0 1 1 Increase in actuator power Increase preload 1 1 1 1 0 0 0 0 Reducing preload 0 0 0 0 1 1 1 1

• 1 means condition fulfilled, 0 means condition not fulfilled.

If, as a preferred embodiment, an angular contact ball bearing, in particular a single-row angular contact ball bearing, in particular a spindle bearing, can be implemented in particular the following variants:

Variants with transmission of the actuating force to the outer ring: After only compressive forces can be generated and transmitted by the active bearing device, it is firstly possible to arrange the conversion device so that the bias voltage is increased by activation of the EAP actuator device. This refinement has the advantage that the conversion device or the active bearing device can be installed overall with a minimal preload, which can be increased to the desired control value in a controlled manner via the EAP actuator device. In the event that the EAP actuator device is deactivated or fails, the minimum bias voltage always remains. Alternatively, the conversion device can be arranged so that by activating the EAP actuator device, the bias voltage is lowered. In this embodiment, the conversion device or the active storage device is installed as a whole so that when the EAP actuator device is deactivated, a maximum bias voltage is set.

This embodiment has the advantage that the maximum preload is chosen as the emergency running property. In both possible variants, it is conceivable that the EAP actuator device is arranged radially on the outside or radially inward to the adjusting elements.

Variants with transmission of the actuating force to the inner ring:
The same variants are also possible with corresponding effect if the conversion device transmits the actuating force to the inner ring.

For the installation of the active bearing device, it is possible - in particular if the active bearing device is designed so that when the EAP actuator device is deactivated, the maximum bias prevails - to activate the EAP actuator device during installation, so that the installation bias is minimal.

In addition to the use of an active bearing device with adjustable bias, an application is possible in which the bias voltage is varied so much that the active bearing device acts as a bearing brake. In this embodiment, the bias voltage is increased until the storage device "jams".

Brief description of the drawings

Further features, advantages and effects of the invention will become apparent from the following description of preferred embodiments of the invention.

Showing:

1a , b shows a schematic longitudinal section of a conversion device with an actuator device for an active bearing device as a first embodiment of the invention;

2 a schematic cross section along a section line to the conversion device in the 1a , b;

3a - 3g Different variants of the conversion device with the actuator device of 1a , b;

4a - 4c Various variations of the active bearing device in the 1a , b.

Detailed description of the drawings

The 1a , b show two states of an active storage device 1 in a longitudinal sectional view along a bearing axis L as an embodiment of the invention.

The storage device 1 includes a storage facility 2 , an actuator device 3 and a conversion device 4 , The storage facility 2 is formed as a radial bearing whose axis of rotation coincides with the bearing axis L, or defines this. The storage facility 2 is realized as an angular contact ball bearing and comprises an outer ring 5 as well as an inner ring 6 , between which balls as rolling elements 7 arranged in a single row. In the training as angular contact ball bearings, the pressure angle D of the bearing device extends 2 angled to the bearing axis L.

Such storage facilities 2 are often or even regularly installed with a defined bias in the axial direction with respect to the bearing axis L in a surrounding construction. The bias voltage is achieved by acting in the axial direction of the inner ring 6 or the outer ring 5 relative to the other bearing ring 5 . 6 loaded.

The active storage device 1 allows the bias voltage to be controlled or controlled via the actuator device 3 as explained below:

The actuator device 3 is designed as an EAP actuator device and is constructed of electroactive polymers, which via an electrical line 8th be subjected to an electrical voltage. As can be seen in particular from the 2 results in a cross section perpendicular to the bearing axis L by the actuator device 3 shows is the actuator device 3 designed as a continuous actuator ring. By applying an electrical voltage changes the actuator device 3 their volume. As shown, the actuator device 3 constructed of concentric and coaxial with each other layers of electroactive polymers, so that the volume change is strongly characterized by a generation of a radial stroke and thus a generation of a radially directed actuator force.

The actuator device 3 is in the conversion facility 4 arranged, which has a first and a second clamping ring 9 . 10 having. In this embodiment, the first clamping ring 9 on the side of the storage facility 2 and immediately with the outer ring 5 contacting and the second bearing ring 10 arranged on the other side of the actuator. The clamping rings 9 . 10 For example, they may be formed as forming rings. Together they form an annular receptacle 11 in which the actuator device 3 inserted and guided laterally. The clamping rings 9 . 10 are formed independently of each other. Optionally, between the clamping rings 9 and 10 seals on both the radial and radial inside, such as gaskets 12 be arranged. The electrical supply line 8th is from the actuator device 3 between the clamping rings 9 . 10 carried out.

The conversion device 4 includes adjusting elements 13 , which are formed as wedge segments. Each of the wedge segments 13 extends in the circumferential direction about the bearing axis L - as from 2 can be seen - over an angular extent of approx. 30 Degree, being between the wedge segments 13 a sufficient distance is fixed. In the in the 1a , b shown longitudinal sectional view can be seen that the wedge segments shelves 14a , B, which are the wedge surfaces of the control elements 13 form. The shelves 14a , B are each inclined by a wedge angle α relative to a plane perpendicular to the bearing axis L radial plane. The shelves 14a , b are in the in the 1a , b embodiment shown in the direction of the bearing axis, ie radially inwardly, arranged converging to each other. In the longitudinal section shown are the control elements 13 trapezoidal shaped.

The clamping rings 9 . 10 have contrasting surfaces 15a , B on, which are also designed as wedge surfaces. In particular, the counter surfaces 15a , b parallel and surface contacting to the shelves 14a , b trained. Also the counter surfaces 15a , B are inclined as wedge surfaces with the angle α relative to the radial plane perpendicular to the bearing axis L.

During operation of the active bearing assembly is by the actuator device 11 generates a radially acting actuator force A, which the adjusting elements 13 moved in the radial direction. Through the through the control elements 13 and the counterparts 15a b formed wedge mechanism, the radially acting actuator A is translated into an axially acting force S. In the active bearing device is the second clamping ring 10 stationary or stationary in the surrounding structure, so that the actuating force S on the outer ring 5 the storage facility 2 acts and the bias in the bearing device 2 reduced in this embodiment.

In the clamping rings 9 . 10 is a paragraph 16 introduced, which an end stop for the adjusting elements 13 forms. By the paragraph 16 As an end stop, it is ensured that even if the power supply to the actuator device fails 3 the control elements 13 can be moved back radially outward only to the end stop, so as to ensure that a maximum bias in the storage facility 2 is not exceeded. In the 1b is the active storage device 1 shown again, wherein by the actuator device 3 the control elements 13 have been moved in the radial direction and by the wedge mechanism of the clamping ring 9 has been displaced in the axial direction, so that the bearing preload in the bearing device 2 is degraded.

The 3a -G show different variants for the installation position of the actuator device 3 as well as the execution of the conversion device 4 , So is in 3a shown that the actuator device 3 relative to the actuator 13 is arranged radially inside, so that upon activation of the actuator device 3 the actuator 13 is moved radially outward. By adjusting the wedge angle α, which are now designed to converge radially outward, an axially acting force S is generated by the actuator A again.

In the 3b corresponds to the mounting position of the actuator device 3 and the training of the converter 4 again the embodiment in the 1a , b, wherein additionally a spring device 17 is provided, which a spring force or restoring force against the actuating element 13 applies. In particular, the spring force F of the spring device 17 aligned in the opposite direction to the actuator force A. After the actuator device 3 can apply only compressive forces, but can not generate tensile forces is by the spring means 17 ensured that the control elements 13 upon deactivation of the actuator device 3 be returned to the starting position.

The 3c shows the training in the 3a also with a spring device 17 wherein the spring means radially outwardly to the actuating elements 13 is arranged.

In the 3d , the the 3b corresponds, is instead of the spring device 17 a second EAP actuator device 18 provided so that the adjusting elements 13 active both radially outward and radially inward can be driven.

In the 3e Another variant is shown, which is the variant in the 3c corresponds, wherein also the spring device 17 by a second EAP actuator device 18 was replaced.

The 3f shows an alternative, with respect to the arrangement in the 3b the orientation of the control elements 13 was swapped, so by the actuator device 3 the force S is lowered.

The 3g shows a variant, wherein the actuator device 3 and the spring device 17 the same radial position as in the 3c However, where the adjusting elements as in the 3f are oriented and activation of the actuator device 3 leads to a lowering of the force S.

The conversion device 4 can - as in the 1a shown on the outer ring 5 act and reduce the bearing preload during expansion. Alternatively, the conversion device 4 according to 4a on the other axial side of the outer ring 5 be arranged and increase the bearing preload when expanding. As further alternatives, the conversion device 4 also on the inner ring 6 act, so that optionally - depending on the attack side - the bearing preload according to 4b lowered or according to 4c is increased. Instead of the illustrated version of the conversion device 4 according to the 1a can any of the alternatives in the 3a - 3g be used.

LIST OF REFERENCE NUMBERS

1

 bearing device

2

 Storage facility

3

 actuator device

4

 conversion means

5

 outer ring

6

 inner ring

7

 rolling elements

8th

 electrical line

9

 first clamping ring

10

 second clamping ring

11

 annular recording

12

 Sealing boots

13

 Control elements (wedge segments)

14a, b

 shelves

15a, b

 counter shelves

16

 paragraph

17

 spring means

18

 EAP actuator device

α

 wedge angle

A

 actuator force

F

 spring force

L

 bearing axle

S

 force

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

• WO 2012/097962 A2 [0004]

Claims (10)

Active storage device ( 1 ), consisting of a storage facility ( 2 ), which has at least one bearing ring ( 5 . 6 ), wherein the storage device ( 2 ) and / or the bearing ring ( 5 . 6 ) defines a bearing axis (L) and from an actuator device ( 3 ) for generating an actuator force (A) and from a conversion device ( 4 ) for converting the actuator force (A) in one in an axial direction with respect to the bearing axis (L) on the bearing ring ( 5 . 6 ) acting actuating force (S), characterized in that the actuator device ( 3 ) is designed as an EAP actuator device with electroactive polymers. Active storage device ( 1 ) according to claim 1, characterized in that the conversion device ( 4 ) as a wedge mechanism with in the radial direction to the bearing axis (L) by the EAP actuator device ( 3 ) movable control elements ( 13 ) is formed, wherein the adjusting elements ( 13 ) in the axial direction acting surfaces ( 14a , b), so that the radial actuator force (A) is converted into the axial actuating force (S). Active storage device ( 1 ) according to one of the preceding claims, characterized in that the EAP actuator device ( 3 ) is formed as a continuous ring or as a plurality of stack actuators. Active storage device ( 1 ) according to one of claims 2 or 3, characterized in that the conversion device ( 4 ) at least one clamping ring ( 9 . 10 ), wherein on the clamping ring ( 15a , b) counter surfaces ( 15a , b) to the shelves ( 14a , b) are arranged. Active storage device ( 1 ) according to claim 4, characterized in that the adjusting elements ( 13 ) as wedge segments and / or the counter surfaces ( 15a , b) is designed as wedge surfaces or are. Active storage device ( 1 ) according to one of claims 4 or 5, characterized in that the at least one clamping ring ( 9 , 10) an end stop ( 16 ) for the control elements ( 13 ) has disabled EAP actuator device. Active storage device ( 1 ) according to one of claims 2 to 6, characterized by a spring device ( 17 ) for biasing the adjusting elements ( 13 ), wherein the biasing force is directed against the direction of the actuator force (A). Active storage device ( 1 ) according to one of the preceding claims, characterized in that the bearing ring ( 5 . 5 ) as an outer ring ( 5 ) or as an inner ring ( 6 ) is trained. Active storage device ( 1 ) according to one of the preceding claims, characterized in that the EAP actuator device ( 3 ) radially inward to the actuating elements ( 13 ) are arranged and act radially outward or that the EAP actuator device ( 3 ) radially on the outside to the actuating elements ( 13 ) are arranged and act radially inward. Active storage device ( 1 ) according to one of the preceding claims, characterized in that the bearing device ( 2 ) is designed as a spindle bearing.

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