SPINNING ROTOR SHAFT, BEARING ARRANGEMENT FOR THE ACTIVE MAGNETIC SUPPORT OF SUCH A SPINNING ROTOR SHAFT AND SPINNING ROTOR DRIVE DEVICE

Abstract

A bearing arrangement (100) for a spinning rotor shaft (200) of an open-end spinning device, a spinning rotor shaft (200) for such a bearing arrangement (100) and a spinning rotor drive device comprising such a bearing arrangement (100) and such a spinning rotor shaft (200). The bearing arrangement (100) comprises at least one active magnetic radial bearing (110) for the spinning rotor shaft (200) which can be influenced by means of an electronic control system (300). The bearing arrangement is characterized in that the bearing arrangement (100) comprises an active magnetic axial bearing (130) for the spinning rotor shaft (200) which can be influenced by means of the or another electronic control system (300).

Claims

1. Bearing arrangement (100) for a spinning rotor shaft (200) of an open-end spinning device, wherein the bearing arrangement (100) comprises at least one active magnetic radial bearing (110) for the spinning rotor shaft (200) which can be influenced by means of an electronic control system (300), characterized in that the bearing arrangement (100) comprises an active magnetic axial bearing (130) for the spinning rotor shaft (200) which can be influenced by means of the or another electronic control system (300).

2. Bearing arrangement (100) according to claim 1, characterized in that the bearing arrangement (100) comprises a bearingless motor (150) for driving the spinning rotor shaft (200), which is also set up as a further or as the at least one active magnetic radial bearing.

3. Bearing arrangement (100) according to claim 1 or 2, characterized in that the active magnetic axial bearing (130) is arranged to be positioned opposite a casing surface section (204, 206) of the spinning rotor shaft (200) to be supported, which casing surface section is designed to be step-like in cross-section, wherein the active magnetic axial bearing (130) comprises at least one first electromagnet (131) for arranging opposite a first casing surface section (204), designed to be step-like in cross-section, for producing a first magnetic force effect directed inside the spinning rotor shaft (200) to be supported along its axis of rotation (220) and a second electromagnet (132) for arranging opposite a second casing surface section (206), designed to be step-like in cross-section, for producing a second magnetic force effect directed inside the spinning rotor shaft (200) to be supported along the axis of rotation (220) of the first magnetic force effect direction.

4. Bearing arrangement (100) according to claim 3, characterized in that at least the first (131) or second electromagnet (132) is arranged to be positioned opposite a casing surface section (204; 206) of the shaft end (210) of the spinning rotor shaft (200) to be supported, which casing surface section is designed to be step-like in cross-section.

5. Bearing arrangement (100) according to claim 1 or 2, characterized in that the active magnetic axial bearing (130) is arranged to be positioned opposite an end face shaft end (210) of the spinning rotor shaft (200) to be supported, wherein the active magnetic axial bearing (130) comprises either a permanent magnetic pole (136) for charging the end face shaft end (210) with magnetic force or a magnetic flux conducting material (135) for interacting with a magnetic force coming from a permanent magnetic pole (208) arranged in the end face shaft end (210) and an electromagnet (133) for transmitting the magnetic force as required, wherein the bearing arrangement (100) is configured for supporting the spinning rotor shaft (200) in a magnetically pretensioned manner in a direction opposite the direction of the magnetic force effect.

6. Bearing arrangement (100) according to claim 1 or 2, characterized in that the active magnetic axial bearing (130) either has a permanent magnetic pole (136) for charging an end face shaft end (210) with magnetic force or a magnetic flux conducting material (135) for interacting with magnetic force coming from a permanent magnetic pole (208) arranged in the end face shaft end (210) and an electromagnet (133) for producing a stabilising axial electromagnetic force overlayering the magnetic force, wherein the permanent magnetic pole (136) or the magnetic flux conduting material (135) is arranged to be positioned opposite an end face shaft end (210) of the spinning rotor shaft (200) and the electromagnet (133) is arranged to be opposite a casing surface section of the spinning rotor shaft (200) designed to be step-like in cross-section.

7. Spinning rotor shaft (200) for the active magnetic support of a bearing arrangement (100) according to claim 1 or 2, characterized in that the spinning rotor shaft (200) is made from a magnetic flux conducting material at least in some shaft sections, through which in the supported state electromagnetic fluxes flow for the axial and radial bearing of the spinning rotor shaft (200).

8. Spinning rotor shaft (200) according to claim 7, characterized in that the spinning rotor shaft (200) is designed to be circular cylindrical as a smooth shaft at least outside the shaft sections provided for conducting the electromagnetic fluxes providing the radial support.

9. Spinning rotor shaft (200) according to claim 7, characterized in that at least one shaft section designed for axially conducting the radial incoming and outgoing electromagnetic flux is a component separate from the spinning rotor shaft (200) which can be mounted on the spinning rotor shaft (200).

10. Spinning rotor shaft (200) according to claim 7, characterized in that the spinning rotor shaft has in some shaft sections, which are provided for interacting with a catching or limiting bearing, a diameter that is smaller than adjacent shaft sections.

11. Spinning rotor shaft (200) according to claim 7 for the active magnetic support of a bearing arrangement (100) according to claim 3, characterized in that the spinning rotor shaft (200) in an effective area of the first (131) and second electromagnet (132) comprises respectively a casing surface section (204, 206) designed to be step-like in cross-section for producing opposing reluctance forces.

12. Spinning rotor shaft (200) according to claim 7 for active magnetic support of a bearing arrangement (100) according to claim 5 or 6, characterized in that the spinning rotor shaft (200) is formed on an end face shaft end (210) provided for arrangement opposite the active magnetic axial bearing (130) from a magnetic flux conducting material (207) or comprises a permanent magnetic pole (208) for producing a magnetic force of attraction acting between the permanent magnetic poles (136, 208) or between the permanent magnetic pole (136; 208) and the magnetic flux conducting material (207; 135).

13. Spinning rotor drive device for an open-end spinning device comprising a drive housing with a bearing arrangement (100) according to claim 1 in connection with a corresponding spinning rotor shaft (200) according to claim 7.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Preferred example embodiments of the invention are explained in more detail in the following with reference to the accompanying drawings, wherein:

[0032] FIG. 1 shows a schematic representation of a bearing arrangement with a spinning rotor shaft according to a first example embodiment;

[0033] FIG. 2 shows a schematic representation of a bearing arrangement with a spinning rotor shaft according to a second example embodiment;

[0034] FIG. 3 shows a schematic representation of a bearing arrangement with a spinning rotor shaft according to a third example embodiment;

[0035] FIG. 4 shows a schematic representation of a bearing arrangement with a spinning rotor shaft according to a fourth example embodiment;

[0036] FIG. 5 shows a schematic representation of a bearing arrangement with a spinning rotor shaft according to a fifth example embodiment; and

[0037] FIG. 6 shows a schematic representation of a bearing arrangement with a spinning rotor shaft according to a sixth example embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0038] In the following description of example embodiments according to the present invention the same or similar reference numerals are used for the similarly acting elements shown in the different figures, wherein said elements are not described more than once.

[0039] FIGS. 1 to 6 show in a schematic representation a bearing arrangement 100 with a spinning rotor shaft 200 according to a first to sixth example embodiment.

[0040] The bearing arrangement 100 according to the first example embodiment shown in FIG. 1 comprises two active magnetic radial bearings 110 which in an arrangement direction frame both sides of a motor 120 for driving the circular cylindrical spinning rotor shaft 200 designed as a smooth shaft. The motor 120 is a conventional direct current motor commutated accordingly for the rotary drive of a spinning rotor shaft with a winding package 122 in the stator and a permanent magnet 124 coupled to the spinning rotor shaft 200 in the rotor.

[0041] The respective active magnetic radial bearing 110 is usually designed to have a stator and a rotor. The rotor is made from an electromagnetic flux conducting material 114 and recessed in the casing surface 202 of the spinning rotor shaft 200. In the stator windings 112 are arranged for producing an electromagnetic field distributed evenly around the spinning rotor shaft 200 such that the controllable magnetic forces produced by the windings 112 work radially relative to the rotor 114 in order to hold the spinning rotor shaft 200 in position.

[0042] The bearing arrangement 100 also comprises an active magnetic axial bearing 130, which is arranged on a side of the bearing arrangement 100 remote from a rotor cup for lying opposite a shaft end 210 of the spinning rotor shaft 200. The active magnetic axial bearing 130 comprises a first 131 and second electromagnet 132 each with a winding 134 rotating around the shaft end 210 for producing axially working magnetic forces. The active magnetic axial bearing 130 is controlled such that the magnetic forces produced by the electromagnets 131, 132 are opposed, in order to enable a stable axial positioning of the spinning rotor shaft 200 by overlayering the magnetic forces. Both the active magnetic radial bearing 110 and also the active magnetic axial bearing 130 are controlled by a common electronic control system 300. The structure of a control system for controlling the position of a spinning rotor shaft is standard. A special feature of the bearing arrangement 100 according to the present invention is that in the shown example embodiments both the respective active magnetic radial bearing 110 and the active magnetic axial bearing 130 are controlled by an, in particular common, control system 300 for positioning the spinning rotor shaft 200 in a stable bearing position. Such a control system 300 comprises in a known manner axial and radial position sensors for detecting the radial or axial position of the spinning rotor shaft 200 a measurement amplifier coupled to the latter for amplifying the measurement signals transmitted by the sensors and a signal processor for processing the measurement signals. The signal processor is coupled on the output side to a power amplifier, by means of which corresponding control signals for moving the spinning rotor shaft 200 out of a current position to a desired position are emitted and transmitted to the active magnetic radial 110 and axial bearing 130.

[0043] Preferably also more than one control system can be used to control said active magnetic bearing. Here in a particularly preferred manner one or more control systems can be designed redundantly, in order to take over control of the components controlled by the latter if there is a defect in the control system, and also to check optionally or alternatively during operation the regulation of a control system.

[0044] The bearing arrangement 100 according to this first example embodiment also comprises an axial limiting bearing 140 known for example from document DE 10 2007 028 935 A1, which bearing supports an axial position sensor which is coupled to the control system 300 and acts on the shaft end 210. The shaft end 210 comprises for the function of limiting an extension 212 projecting from the latter along the axis of rotation and projecting into the limiting bearing 140.

[0045] The spinning rotor shaft 200 is designed as a whole to be circular cylindrical as a smooth shaft. The external diameter of the spinning rotor shaft 200 defining the circular cylinder is thereby not projected over by a projection assigned to the spinning rotor shaft 200 and projecting radially from the latter. In this way the bearing arrangement 100 can be designed to be extremely compact in radial bearing direction.

[0046] The spinning rotor shaft 200 comprises at its shaft end 210, which faces away from the rotor cup-side end, in the region of the active magnetic axial bearing 130 respectively a constriction, by means of which the casing surface 202 in a section 204, 206 opposite the active magnetic axial bearing 130 is designed to be step-like in cross-section. The step-like contour generates reluctance forces, which with the suitable control of the active magnetic axial bearing 130 enable a correction of the axial position of the spinning rotor shaft 200.

[0047] In the region of the motor 120 the spinning rotor shaft 200, as described above, is provided with a permanent magnet 124 in the rotor of the motor 120. In the respective area of the active magnetic radial bearing 110 a magnetic flux conducting material is embedded into the casing surface 202 of the spinning rotor shaft 200.

[0048] The second example embodiment shown in FIG. 2 differs from the first example embodiment only in the configuration of the motor. In the second example embodiment a bearingless motor 150 is used, which in addition to the drive component also takes over a radial bearing component, whereby the bearing arrangement 100 according to the second example embodiment is physically reduced compared to the bearing arrangement 100 according to the first example embodiment by an active magnetic radial bearing. Such a bearingless motor 150 is usually designed such that a four-pole support field is produced opposite a two-pole rotor field, so that the magnetic forces required for radial bearing can be produced in the active part of the bearingless motor 150. The use of the bearingless motor 150 enables the simplification of the structure of the bearing arrangement. Only the position sensor and the position control are retained by the control system 300.

[0049] FIG. 3 shows a third example embodiment of a bearing arrangement 100 which differs from the second example embodiment by a further reduction of an active magnetic radial bearing and by a different arrangement of the electromagnets 131, 132 of the active magnetic axial bearing 130. The electromagnets 131, 132 are arranged on both sides of the bearingless motor 150. Said bearing arrangement 100 is particularly advantageous for short spinning rotor shafts 200. Due to the fact that the active magnetic axial bearing 130 produces a radial magnetic force component as well as an axial magnetic force component, the radial magnetic force component can be used for radially supporting the spinning rotor shaft 200.

[0050] The spinning rotor shaft 200 according to this third example embodiment differs from the spinning rotor shafts 200 according to the first and second example embodiment by the design of the casing surface, which is step-like in cross-section, in a section of the spinning rotor shaft 200 satisfying the changed arrangement of the active magnetic axial bearing 130.

[0051] FIG. 4 shows, unlike the second example embodiment, a bearing arrangement 100 according to a fourth example embodiment with an alternative configuration of the active magnetic axial bearing 130 and the assigned shaft end 210 of the spinning rotor shaft 200. This variant can also be used in particular in an alternative manner in one of the other two example embodiments. The alternative variant of the active magnetic axial bearing 130 is arranged to be positioned opposite the end face shaft end 210 of the spinning rotor shaft 200 to be supported and comprises a permanent magnetic south pole 136 for charging the end face shaft end 210 with a magnetic force and an electromagnet 133 for overlayering if necessary the permanent magnetic force. The spinning rotor shaft 200 according to this fourth example embodiment comprises on the end face shaft end 210 provided on the opposite arrangement relative to the active magnetic axial bearing 130 a permanent magnetic north pole 208 for producing a magnetic force of attraction acting between the different permanent magnetic poles. The permanent magnetic north pole 208 is embedded in the end side shaft end 210.

[0052] Furthermore, the bearing arrangement 100 is designed according to the fourth example embodiment to support the spinning rotor shaft 200 in a magnetically pretensioned manner in a direction opposite the effective direction of the magnetic force of attraction. This can be achieved for example in that in a non-operating state of the bearingless motor 150 the winding 152 provided in the stator is arranged offset in axial bearing direction to the rotor 154. In an operating state of the bearingless motor 150 then magnetic pretensioning forces acting in a axial bearing direction are produced, which act against the force of attraction of the active magnetic axial bearing 130. The offset is selected in particular such that in the shown operating state of the bearing arrangement 100 the offset between the winding 152 and rotor 154 is removed.

[0053] FIG. 5 shows with the fifth example embodiment an alternative variant to the fourth example embodiment with the only difference being that the spinning rotor shaft 200 instead of a permanent magnetic pole comprises a magnetic flux conducting material 207, which is in magnetic interaction with the permanent magnetic south pole 136 of the active magnetic axial bearing 130.

[0054] FIG. 6 shows a sixth example embodiment with a variant of an active magnetic axial bearing 130 alternative to the fourth example embodiment and a spinning rotor shaft 200 provided for this. The active magnetic axial bearing 130 comprises a magnetic flux conducting material 135, which is arranged to be opposite a permanent magnetic south pole 208, which is arranged in the end face shaft end 210 of the spinning rotor shaft 200, in order to generate magnetic forces of attraction in axial bearing direction of the spinning rotor shaft 200.

[0055] Furthermore, an electromagnet 133 is assigned to the active magnetic axial bearing 130, which is arranged, like the electromagnet 131, 132 of the first to third example embodiments to be opposite a step-like casing surface section 209, in order to produce reluctance forces in axial bearing direction. The electromagnet 133 is configured and can be controlled to produce in the axial bearing direction of the magnetic force of attraction opposing forces for stabilising the axial bearing position of the spinning rotor shaft 200. In this way the structure of the bearing arrangement 100 can be simplified compared to the fourth and fifth example embodiment, as the electromagnet 133 assigned to the active magnetic axial bearing 130 in this arrangement effectively replaces the aforementioned magnetic pretensioning.

[0056] In a not shown alternative way to the sixth example embodiment the magnetic flux conducting material of the active magnetic axial bearing 130 according to a further example embodiment can be replaced by a permanent magnetic pole, which is magnetised differently from the permanent magnetic pole 208 arranged in the end face shaft end 210. Furthermore, according to a further example embodiment the end face shaft end 210 can comprise instead of the permanent magnetic poles a magnetic flux conducting material, wherein the active magnetic axial bearing 130 opposite the magnetic flux conducting material comprises a permanent magnetic pole. In principle, any variant is possible, provided that between the end face shaft end 210 of the spinning rotor shaft 200 and the component opposite the latter of the active magnetic axial bearing 130 a magnetic force acting in axial bearing direction can be produced.

[0057] The example embodiment described and shown in the figures are only selected by way of example. Different example embodiments can be combined with one another completely or only with respect to individual features. Also an example embodiment can be supplemented by features of a further example embodiment. Thus for example the arrangement of the active magnetic radial bearing and/or the active magnetic axial bearing is not restricted to the representations shown in FIGS. 1 to 6. Also the active magnetic axial bearing 130 can be configured so that the windings 134 of the respective electromagnet 131, 132 are parallel to an axis of rotation 220 of the spinning rotor shaft 200. Furthermore, in principle in all of the example embodiments the usual previously known catching and/or limiting bearing can be provided in order to ensure the secure operation of the spinning rotor shaft 200 by preventing the pulling out of the spinning rotor shaft 200 for example in the case of a defect of the bearing arrangement 100.

[0058] If an example embodiment has an “and/or” link between a first feature and a second feature, this can be interpreted to mean that the example embodiment according to one embodiment comprises both the first feature and also the second feature and according to a further embodiment comprises either only the first feature or only the second feature.

[0059] It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiment, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.