DE102009020384A1 - Bearing arrangement e.g. radial axial-thrust bearing, for machine table, has rotor movably supported by stator, where rotor and stator are pushed with respect to each other in area of contact areas - Google Patents

Abstract

The arrangement has a rotor (03) movably supported by a stator (01). The rotor and the stator exhibit opposite contact areas (07). A gap (09) is formed between the contact areas, and is filled with hydraulic fluid. The rotor and the stator are pushed with respect to each other in an area of contact areas by a permanent magnet (11). The stator and the rotor form a planar switched torque motor. A roller bearing (05) is provided between the stator and the rotor. The magnet is formed by magnetic attraction forces between primary and secondary parts of a planar arranged torque motor.

Description

The The invention relates to a storage arrangement for a machine table according to the preamble of claim 1.

typical Areas of application of the invention are mounted linear guides And rotary tables, especially axes of all kinds, the high Load and weight load are subjected, which without suitable Compensation for a significant reduction in the life of the Storage can lead. Possible applications for the present invention are in tool, textile and printing presses, special machines, conveyor systems, workpiece carrier circulation systems, Food, bottling and packaging equipment to see.

The DE 10 2006 036 051 A1 discloses a Rundtischlagerungs- and drive device with a rotatably mounted on a frame round table, for the storage of an axial-radial roller bearing and an active magnetic bearing are provided, which is understood to mean a working with electromagnet magnetic bearing. The magnetic bearing is preferably arranged radially outside of the axial-radial rolling bearing and connected to a control unit, which in turn receives sensor signals from at least one of the position and / or the state of motion of the rotary table detecting sensor. Based on the control of the magnetic bearing by the control unit counter forces are generated to compensate for the mechanical vibrations occurring during operation of the rotary table. A disadvantage of the active magnetic bearing is its complex design, both in terms of the mechanics and the electrical control circuit and the scheme.

From the DE 10 2006 053 041 A1 a storage arrangement is known, in particular for a machine tool, with a stator and a relative to this movably mounted rotor, which comprises a roller bearing and a magnetic bearing. The magnetic bearing has a plurality of permanent magnets, which are spaced from each other connected to the stator or rotor and separated by an air gap, wherein the opposite, relative to each other movably mounted permanent magnets on their sides facing each other always have the same poles. As a result, magnetic repulsion forces are generated between the permanent magnets, which causes a relief of the rolling bearing. This passive magnetic bearing is simpler in design and function compared to an active magnetic bearing. However, it is disadvantageous that it only supports in one direction.

From the DE 10 2005 024 004 A1 is a pivot bearing device, in particular for a rotatable rotary table of a machine tool, known with at least one rolling bearing on which an axial force acts. To generate a substantially oppositely directed compensation force, a magnetic device is provided. An embodiment of this magnetic device comprises a plurality of permanent magnets which are arranged opposite one another on a first rotatable device part preferably connected to the rotary table and on a second device part standing relative to the first device part, the permanent magnets being aligned with their poles in such a way that they attract each other. In a further embodiment of this rotary bearing device, the magnetic device is formed by the permanent magnets of the disc-shaped rotor of a running as a pancake torque motor, which is used for direct drive of the rotary table. This achieves an integrated direct drive as well as the magnetic relief of the rolling bearing.

So called squeeze film damper, where an oil film between bearing parts dampens vibrations are from the Machine tool construction known.

From the company brochure: "EMO News 2007", 2007-09, Schaeffler KG , a damping element is known whose operation is based on the squeeze effect. The rolling bearing of a rotary table is connected to the outer ring with an additional disc, so that a defined narrow gap is formed between this disc and the rotating face plate of the rotary table. A thin oil film encapsulated by a sealing system separates the rotating rotary table from the fixed damping element.

Hydrostatic or magnetic bearings are predominantly used in linear guides, especially at high loads, and when friction forces, - Moments and heat are disturbing, used. at Rotary tables these camps work in one direction only supportive.

The The object of the invention is thus to provide an improved storage arrangement to create for machine tables, which is a compensation the mechanical vibrations of the machine table and the discharge advantageous from the mechanical forces acting through the machine table combined and relieved the rolling bearing.

The This object is achieved by a storage arrangement for a machine table according to the attached Claim 1 solved.

The Inventive storage arrangement has a Stator and a relative to this movably mounted runner with the rotor and the stator facing each other Have contact surfaces, between which one with hydraulic fluid fillable gap is formed. Furthermore, the storage arrangement provided with a magnetic means through which the rotor and the stator in the region of the contact surfaces on each other are too crowded.

In a first preferred embodiment is the fillable Split a squeeze film damper. The magnet means is through the magnetic attractions between primary and secondary part of a planar designed Torgemotors (pancake motor) educated. In this embodiment, in the radial / axial rotary table bearing be dispensed with an axially acting bearing row. This means one reduced material and maintenance costs.

The Contact surfaces of the squeeze film damper are preferably made of steel, but can also be made of others Metals, such as non-ferrous metal, of plastics or Ceramics be executed. The runner and the stator preferably form a torque motor with internal rotor, although other embodiments, such as. B. torque motor with external rotor are possible. The runner is preferably by means of an axial-radial cylindrical roller bearing stored relative to the stator. However, come in modified Embodiments also other types of bearings, such. B. Double row angular contact ball bearings are used.

In a second preferred embodiment of the invention the axial bearing is realized by a hydrostatic bearing, which supports the turntable in the vertical direction. The magnetic means are arranged opposite each other within the contact surfaces, mutually attracting permanent magnets through which the hydrostatic Bearing is biased in the axial direction. This is the hydrostatic Bearing not only loadable in both directions, but points at the same time a higher tilt stiffness than a pure hydrostatic bearing. In this embodiment can advantageously completely can be dispensed with the axial bearings. The hydrostatic Bearing is through inlet and outlet bores with a Hydraulikversogungsmittel connected.

In In this embodiment, the contact surfaces in addition to the above materials also made Be made ceramic.

The Contact surfaces of the storage arrangement have for the hydrostatic bearing at least one inlet and one drain hole on, by which hydraulic fluid with a controllable Pump is pumped into the gap, taking values for the Hydraulic pressure up to 600 bar are possible.

In Another preferred embodiment is the hydraulic supply Squeeze Film Damper or Hydrostatic Bearing with connected to a cooling device for the stator.

Preferably the inlet and outlet bores are in series with cooling channels connected to the stator, wherein a parallel circuit of the hydrostatic Warehouse and the coolant supply also possible is. In both cases, the hydraulic fluid must (eg oil) have properties which are simultaneous Use to cool the stator.

The Hydraulic fluid gets into the gap between the contact surfaces directed, where it spreads and by internal friction at swinging machine table a damping and an axial counterforce on the storage causing, resulting in at least a slight warming the hydraulic fluid results. The hydraulic fluid continues to the stator, absorbing heat loss, which arises in the stator windings. From there, the hydraulic fluid passes the at least one drain hole back into a hydraulic unit. The hydraulic fluid has the task, both to cool the stator as well as the swinging machine table to dampen. In addition, the hydraulic fluid also used for the lubrication of rolling bearings when the circuits are designed accordingly.

A separate cooling of the stator and a separate hydraulic unit to supply the gap with hydraulic fluid also possible. However, this embodiment is more complex and associated with more costs.

The Combined hydraulic power unit for cooling the stator and Supplying the gap with hydraulic fluid or else a separate hydraulic unit can be the following with its main components comprise described arrangement. The hydraulic fluid passes from the at least one drain hole in the tank, from there on a cooling unit or a heat exchanger in a pump. From the pump via a filter, a memory and a Control valve in the at least one inlet bore.

Other equally required for the operation components of the hydraulic unit, such as control and monitoring devices, control panel, display devices and power supply will not be considered here for reasons of clarity. By the mentioned control valve, the supply of hydraulic fluid can be controlled in the flow as well be switched on or off.

About that In addition, in the case of a hydrostatic bearing and the hydraulic fluid supply the bearing can be controlled by the control valve in the flow. This provides the advantage that, for an operating case, in which no damping is required or even disadvantageous could be the gap free of hydraulic fluid can be switched. For example, this can be fast Rotary movements, for maintenance work, in case of emergency failure or be appropriate for machine downtime. At pressure drop or in case of machine downtime, the machine table can go a little way fall, which can be prevented by spacers here, that the adjacent surfaces or the contact surfaces lie completely on each other. In this case would have to a short circuit, if necessary, the cooling circuit for the Engine be maintained.

following becomes the storage arrangement according to the invention in particular for rotary axes, the preferred embodiments mutatis mutandis to be applied to linear axes can.

In the embodiment with hydrostatic bearing of the invention Storage, the magnetic means comprises a stator arranged on the stator permanent magnet group and an opposite one arranged on the rotor Runner permanent magnet group, which on the contact surfaces are applied, wherein the two opposing permanent magnet groups are separated by the gap and on the sides facing each other own different magnetic poles. The permanent magnets can for example, from the magnetic materials NdFeB, SmCo or hard ferrite consist. These are with respect to the contact surfaces vertically magnetized.

Of Further, the stator and rotor permanent magnet groups by radially with each other with non-magnetic filler spaced permanent magnets are formed. The filler may be polymeric potting material such as epoxy resin, polyurethane or silicone as well as ceramic, thermoplastic or glass be.

at rotating axes, the permanent magnets as magnetic rings be executed. By the attractions between the two permanent magnet groups are the rotor and the stator in the region of the contact surfaces towards each other crowded. This will be a relief of storage achieved the rotor applied bearing, wherein the inventive Storage arrangement is loadable in both directions and a has higher Verkippsteifigkeit. This arrangement has the advantages that the axial support hydrostatically realized which increases the life of the storage arrangement as a whole.

in the Contrary to the integration of the magnetic means described above The contact surfaces of the storage arrangement is also a separate version of the magnet means possible. In this case, the magnet means is arranged outside the contact surfaces, which, however, requires a larger installation space.

In a further embodiment of the invention Storage arrangement, the stator and the rotor are as planar switched torque motor executed, wherein the magnetic means is formed by the permanent magnets of the torque motor. At this particular embodiment, the torque motor has a horizontally arranged disc-shaped rotor on and is used for direct drive of the machine table. Here is the integration of the direct drive and the magnetic means advantageous in one unit.

Further Details and specifics of the invention Storage arrangement will become apparent from the following description preferred embodiments, with reference to the Drawing. Show it:

1 a schematic cross-sectional view of a first embodiment of a storage arrangement according to the invention for a machine table;

2 a detailed view of stator and rotor permanent magnet groups of the embodiment according to 1 in cross-section;

3 a schematic cross-sectional view of a second embodiment of the storage arrangement for a machine table.

1 shows a cross-sectional view of a storage arrangement with a hydrostatic bearing for a machine table, which is designed as a rotary table storage arrangement. The storage arrangement comprises a stator 01 and a relative to this movably mounted runner 03 , Between the stator 01 and runners 03 is a radial cylindrical roller bearing 05 provided which can absorb radial forces.

The stator 01 and the runner 03 are with contact surfaces designed as plates 07 which are spaced apart and radially outward of the radial cylindrical roller bearing 05 are arranged. Furthermore, the storage arrangement has an integrated magnetic means. The magnet means comprises one on the stator 01 arranged stator permanent magnet group and one opposite to the rotor 03 arranged runner permanent magnet group, which on the contact surfaces 07 applied or integrally formed therewith, wherein the two opposed permanent magnet groups through a gap 09 are separated and have different magnetic poles on the sides facing each other.

2 shows the construction and the arrangement of the stator and rotor permanent magnet groups of the first embodiment of the storage arrangement in a detailed view. The stator and rotor permanent magnet groups comprise permanent magnets designed as concentric magnet rings 11 , which in the radial direction by a filler 13 spaced from each other on the contact surfaces 07 are arranged. Between through the permanent magnets 11 and the filler 13 certain surfaces remains filled with hydraulic oil gap 09 , The permanent magnets 11 and the filler 13 form level, precise surfaces, which the gap 09 limit with constant width. Furthermore, the stator permanent magnet group has an inlet bore 17 and a drain hole 15 on, which are intended for Hydraulikölzu- and removal. Of course, the gap must be sealed to maintain the hydraulic pressure.

Out 1 is also apparent that the inlet and outlet holes 17 . 15 with cooling channels 19 connected in series, that of a coolant supply to a stator winding 21 allow. The runner 03 and the stator 01 are formed in the illustrated embodiment as a torque motor with internal rotor. The hydraulic oil is via the inlet hole 17 in the gap 09 passed, there in ring channels 23 intercepted and distributed (see 2 ). Next is the hydraulic oil with adjustable pressure through the cooling channels 19 pumped, flows around the stator winding 21 and thus absorbs the heat loss. The hydraulic oil is then through the drain hole 15 led back to the hydraulic unit.

The hydraulic oil thus has twice the function, the stator winding 21 to cool and dampen the mechanical vibrations of the turntable. The attraction forces between the stator and rotor permanent magnet groups are the rotor 03 and the stator 01 in the area of their contact surfaces 07 crowded together. The storage arrangement is thus resilient in both directions and has a high tilting rigidity. This achieves a axia le support of the radial cylindrical roller bearing 05 , Since no such high forces act in the radial direction as in the axial direction, the application of a single-row radial cylindrical roller bearing 05 for centering and guiding the turntable possible.

3 shows a second embodiment of the storage arrangement for a machine table turn in a simplified cross-sectional view. Unlike the in 1 illustrated embodiment, the stator 01 and runners 03 designed as a planar-connected torque motor, wherein the magnetic means by disc-shaped permanent magnets 25 is formed of the rotor, which is horizontal with respect to a horizontally oriented stator winding 27 are arranged. By the magnetic attraction forces between the permanent magnets 25 and the stator winding 27 are the runner 03 and the stator 01 in the area of their contact surfaces 07 crowded together. The runner 03 is here by means of a radial-axial cylindrical roller bearing 29 with respect to the stator 01 stored. By introducing hydraulic oil into the gap 09 is the same as in the embodiment according to 1 Achieved an axial relief of the storage arrangement.

In The illustrated embodiment is the squeeze film damper with the hydraulic oil supply for the Stator cooling coupled. It goes without saying in the context of the invention, the squeeze film damper separately encapsulated.

01

stator

03

runner

05

Radial cylindrical roller bearings

07

contact area

09

gap

11

permanent magnet

13

fillers

15

drain hole

17

inlet bore

19

cooling channel

21

stator

23

annular channel

25

permanent magnet

27

stator

29

Radial-axial cylindrical roller bearings

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

• - DE 102006036051 A1 [0003]
• - DE 102006053041 A1 [0004]
• - DE 102005024004 A1 [0005]

Cited non-patent literature

• - "EMO News 2007", 2007-09, Schaeffler KG [0007]

Claims (14)

Storage arrangement for a machine table with a stator ( 01 ) and a relative to this movably mounted runner ( 03 ), the runner ( 03 ) and the stator ( 01 ) opposing contact surfaces ( 07 ), between which a hydraulic fluid fillable gap ( 09 ), characterized in that it further comprises a magnetic means ( 11 . 25 ), by which the runner ( 01 ) and the stator ( 03 ) in the area of their contact surfaces ( 07 ) are crowded together. Storage arrangement according to claim 1, characterized that it is designed as a linear bearing. Storage arrangement according to claim 1, characterized that it is designed as Rotativlager. Storage arrangement according to claim 2 or 3, characterized in that the magnetic means ( 11 ) one on the stator ( 01 ) Statorpermanentmagnetgruppe and an opposite on the rotor ( 03 ) arranged rotor permanent magnet group, which on the contact surfaces ( 07 ) are applied or formed integrally therewith, wherein the two opposite stator and rotor permanent magnet groups through the gap ( 09 ) are separated and have different magnetic poles on the sides facing each other. Storage arrangement according to Claim 4, characterized in that the stator and rotor permanent magnet groups are formed by radially non-magnetic filling ( 13 ) spaced permanent magnets ( 11 ) are formed. Storage arrangement according to the claim 5 dependent on claim 3, characterized in that the permanent magnets ( 11 ) of the stator and rotor permanent magnet group are designed as magnetic rings. Storage arrangement according to claim 3, characterized in that the stator ( 01 ) and the runner ( 03 ) form a planar connected torque motor, wherein the magnetic means by permanent magnets ( 25 ) of the torque motor is formed. Storage arrangement according to one of claims 1 to 7, characterized in that the contact surfaces ( 07 ) at least one inlet and one drain hole ( 15 . 17 ) exhibit. Storage arrangement according to claim 8, characterized in that the inlet and outlet bores ( 15 . 17 ) in series with cooling channels ( 19 ) of the stator 01 are connected to an external hydraulic supply unit. Storage arrangement according to claim 8, characterized in that the inlet and outlet bores ( 15 . 17 ) in parallel with cooling channels ( 19 ) of the stator ( 01 ) are connected to an external hydraulic supply unit. Storage arrangement according to one of claims 1 to 10, characterized in that the hydraulic fluid adjustable in the gap ( 09 ) is eligible. Storage arrangement according to claim 11, characterized in that the gap ( 09 ) can be switched pressure-free. Storage arrangement according to one of claims 1 to 12, characterized in that further between the stator ( 01 ) and the runner ( 03 ) a rolling bearing ( 05 . 29 ) is provided. Storage arrangement according to claim 13, characterized in that the rolling bearing is a thrust bearing, a radial bearing ( 05 ) or a radial thrust bearing ( 29 ).